UC-NRLF 


llllllllllllillllllllllllllnlHl 


THE  ABC  OF 
PHOTO-xMICROGRAPHY 


By  W.  H.  Walmsley 


.^ 


UNIVEKSi.  CALIFORNIA 

DAVIS 


Digitized  by  the  Internet  Archive 

in  2007  with  funding  from 

IVIicrosoft  Corporation 


http://www.archive.org/details/abcofphotomicrogOOwalmrich 


i 


Trans.  Section  of  Echinus  Spine.     Echinometra  lucunter  -f  ?o 


THE  A  B  C  OF 
PHOTO-MICROGRAPHY 

fur  l^gmn^rfli 


BY 

W.  H.  WALMSLEY,  F.R.M.S.,  F.A.A.A.S. 

CHARTER  MEMBER  AMERICAN  MICROSCOPICAL   SOCIETY,  ETC. 


JJ^fa  fork 

TENNANT    AND    WARD 

1902 


Copyright,    1902 
By  Tennant  &  Ward,  New  York 


'J 


V 


AJJ  rishti  reserved 


.^^"' 


Mount  ffUasant  ^rraa 

J.  Horace  McFarland  Company 
Harrisburg,  Pennsylvania 


PREFACE 

The  only  apology  I  can  offer  for  the  being  of  this  little 
work  is  a  dual  one,  smacking  somewhat  of  egoism.  It 
had  appeared  for  a  long  time  —  to  me  —  that  it  was 
needed,  and  further  that  I  could  fill  the  need.  Acting 
under  this  belief,  or  possibly  delusion,  it  has  been  written; 
whether  successful  as  to  the  second  proposition,  its  read- 
ers must  determine  for  themselves.  There  can  be  no  two 
opinions,  however,  regarding  the  first,  for  it  is  a  matter  of 
fact,  that  in  all  the  world  of  books— so  far  as  my  researches 
have  extended — there  is  not  one  through  which  a  person 
totally  unacquainted  with  the  practical  requirements  of 
Photo-Micrography  can  learn  them.  There  are  some  fairly 
elaborate  works  on  the  subject,  but  one  and  all,  assuming 
their  readers  to  be  fully  acquainted  with  the  alphabet,  as  it 
were, of  the  science  or  art,  start  them  at  the  outset  in  read- 
ing lessons  ere  they  have  learned  to  spell.  The  result  is, 
that  by  hard  work,  much  perseverance  and  many  failures 
alone,  can  they  hope  to  make  acquaintances  with  the  little 
things  of  vital  importance  to  be  done,  or  left  undone  which 
the  books  have  signally  failed  to  teach. 

With  keen  recollections  of  my  own  early  struggles  and 
failures,  I  have  in  these  pages  sought  to  aid  the  novice,  by 
an  earnest  endeavor  to  teach  him  the  A  B  C  of  the  matter 
and  explain  clearly  as  possible  the  simple  but  indispensa- 
ble methods  and  manipulations,  by  which  alone  he  can 
hope  to  arrive  at  any  measurable  success.     The  book  has 

(Hi) 

328443 


IV  PREFACE 

not  been  written  for  advanced  scholars,  but  is  simply  in- 
tended for  kindergarten  use,  as  it  were.  In  furtherance  of 
this  design,  care  has  been  given  to  explain  many  things  so 
simple  that  they  would  seem  to  be  self-evident  to  those 
already  familiar  with  the  requirements  of  Photo-Micro- 
graphy, but  which,  alas,  are  often  insurmountable  obstacles 
to  the  beginner ;  a  feature  quite  ignored  in  all  the  works 
on  the  subject  which  have  come  under  my  notice.  With 
this  explanation  of  its  scope  and  purposes,  the  little  work 
is  put  forth  accompanied  by  the  earnest  hope  that  it  may 
prove  to  be  a  useful  aid  to  many  an  earnest  gleaner  in  the 
ever-broadening  field  of  Photo-Micrography. 

My  earnest  thanks  are  due,  and  herewith  expressed,  to 
the  many  kind  friends  who  have  aided  my  efforts  in  the 
**long  ago*'  by  precept  and  practice.  Among  them  I 
would  especially  name  my  old-time  friend,  Dr.  A.  Clifford 
Mercer,  of  Syracuse,  New  York,  and  Dr.  Wm.  M.  Gray, 
of  the  Army  Medical  Museum,  Washington,  D.  C,  each 
of  whom  has  so  largely  contributed  to  the  advancement  of 
Photo-Micrography,  to  its  present  important  condition  of 
comparative  perfection.  My  thanks  are  also  due,  in  like 
measure,  to  the  publishers,  whose  liberality,  experience 
and  good  taste  have  done  so  much  toward  presenting  the 
little  volume  in  its  present  attractive  form.  And,  I  may 
add  in  conclusion,  that  should  it  meet  with  the  hoped-for 
approval  at  the  hands  of  my  readers,  it  will  probably  be 
followed  by  a  much  fuller  and  more  elaborate  treatise  on 
the  same  subject,  which  has  been  in  course  of  preparation 
for  several  years. 

Philadelphia,  Pa..  July  4,  i9oa. 


CONTENTS 

) 
CHAPTER  '■*<•• 

L     Introductory i 

II.     The  Microscope  and  Optical  Apparatus   .     .  8 

III.  The  Camera  and  Photographic  Appliances     .  i8 

IV.  The  Radiant  and  Illumination 42 

V.     Negative  Making 49 

VI.     Printing  Methods — Lantern  Slides       ...  98 

VII.     General  Notes 119 

Description  of  Plates I45 

Index 149 


(v) 


ILLUSTRATIONS 

NUMBER 

Transverse  Section  of  Echinus  Spine     .     .     . 
Frontispiece     . 

1.  Student  Microscope  and  Portable  Camera.     . 

2.  Adjustable  Camera.     Upright  to  Horizontal 

3.  Walmsley's  Enlarging   and   Reducing  Photo- 

Micrographic  Camera 

4.  Walmsley^s    Camera   and    Microscope,  with- 

out Ocular 

5.  Walmsley's    Camera    arranged    for    Focusing 

with  Microscope 

6.  Walmsley's  Camera  and  Microscope  arranged 

for  High  Powers 

7.  Carcinoma  of  Mammary  Gland 

8.  Suctorial  Tubes,  Tongue  of  Blow -Fly      .     , 

9.  Aulacodiscus  Oreganus.     Diatom      .     .     .     . 

10.  Voluntary  Muscle.     Man 

11.  Karyokinetic  Figure  in  Leucocyte     .     .     .     . 

12.  Pleurosigma  angulatum.     Diatom      .     .     .     . 

13.  Grouped  Anchors  and  Plates  of  Synapta  .     . 

14.  Heliopelta  euleri.     Diatom 

15.  Diatoms  from  Cuxhaven 

16.  Cluster  Cups ;  iEcidium     ....... 

(vii) 


II 

III 

IV 

V 

VI 

VII 


VUl  ILLUSTRATIONS 

NUMBER  PLATE 

'[viii 

IX 


17.  Starch  of  Canna  Root.     Tous  le  Mois 

18.  Crystals  of  Amygdalin -. 

19.  Bacillus  tuberculosis  in  Sputum  .... 

20.  Bacillus  anthracis 

21.  Streptococcus  Pyogenes 

22.  Bacillus  Trommel  -  Schlagel 

23.  Corisa  undulata 

24.  Transverse  Section,  Stem  of  Serjania    .     . 

25.  Mosquito.     Anophele  (Female)    .... 

26.  Human  Scalp.     Flat  Section 

27.  Lantern  Slide,  Front.     Compound  Ovary . 

28.  Lantern    Slide,    Back.      Compound    Eyes   of 

Beetle 


XI 
XII 

XIII 


CHAPTER    I 

Introductory 

The  distinction  between  a  Photo-Micrograph 
and  a  Micro-Photograph  would  seem  to  have 
been  settled  a  good  many  years  ago, —  fully 
a  quarter  of  a  century,  at  least, —  yet  we 
continually  hear  the  latter  name  applied  indis- 
criminately to  either ;  an  illustration  of  persist- 
ence, it  having  preceded  the  former  by  other 
long  years.  As  defined  by  Worcester,  however, 
a  Micro-Photograph  ^4s  a  minute  photograph 
of  any  subject,  so  small  that  its  form  or  details 
are  invisible  to  the  unaided  eye,  requiring  the 
use  of  a  microscope  to  see  them."  A  prac- 
tical illustration  of  these  may  be  found  in 
the  so-called  *^  charms,"  many  of  them  shaped 
like  a  miniature  opera -glass,  containing  a 
Stanhope  lens,  to  the  flat  end  of  which  is 
attached  a  minute  photograph.  On  holding 
it  to  the  light  and  looking  into  the  other  end 
an  enlarged  picture  is  seen.  The  subjects  are 
almost  innumerable  in  variety  and  interest. 
They  are  all  made  in  Paris,  I  believe.  For- 
merly they  were  also  to  be  had  mounted  on  a 

A  (l) 


^  . ,         THE    A    B    C  ^OF    PHOTO  -  MICROGRAPHY 

slip  of  microscopic  glass,  and  were  used  under 
the  microscope;  being  very  favorite  objects; 
and  always  formed  a  portion  of  an  amateur's 
collection  of  slides.  Their  manufacture  was 
carried  to  great  perfection  In  those  days.  I 
have  one  made  by  Langenheim  (a  noted  Phila- 
delphia photographer),  of  the  Lord's  prayer, 
which  is  so  minute  as  to  be  invisible  to  the 
naked  eye.  It  requires  a  magnification  of 
nearly  lOO  diameters  to  be  clearly  read,  under 
which,  each  letter  is  sharply  cut  as  though  done 
by  the  stroke  of  a  pen,  no  granulation  of  the 
silver  being  perceptible.  It  is  a  marvelous 
piece  of  work,  and  probably  could  not  be 
duplicated  at  the  present  day.  But  to  return. 
By  the  same  authority  a  Photo-Micrograph  is 
said  to  be  "  an  enlarged  photograph  of  a 
microscopic  object  produced  by  throwing  its 
Image  through  a  suitable  combination  of  micro- 
scope and  camera."  It  Is  the  latter  class  that 
forms  the  subject  matter  of  this  little  volume, 
and  by  this  means  the  negatives  were  made 
from  which  the  reproductions  that  Illustrate  It 
were  produced.  My  friend.  Dr.  A.  Clifford 
Mercer,  has  given  probably  the  most  concise 
definitions  of  the  two  terms.  He  says  **  a 
micro-photograph  Is  a  microscopic  photograph 
of  a  macroscopic  object.     A  photo-micrograph 


INTRODUCTORY 


IS  a  macroscopic  photograph  of  a  microscopic 
object."  Macroscopic  denotes  an  object  of 
minute  proportions,  but  visible  to  the  naked 
eye,  or  by  means  of  a  pocket  lens,  and  does 
not  require  the  use  of  a  microscope.  An  en- 
larged drawing  of  such  an  object  to  the  extent 
of  a  few  diameters  is  termed  a  macrograph: 
if  made  by  the  aid  of  cameras,  why  not  a 
photo-macrograph?  There  is  an  endless  num- 
ber of  such  objects,  which  may  be  enlarged 
by  the  aid  of  a  suitable  camera  and  photo- 
graphic lens  from  one  to  about  ten  diameters 
—  the  limit  of  a  pocket  lens  of  one-inch  focus. 
I  have  ventured  to  coin  the  word  photo- 
micrograph in  this  connection,  and  descrip- 
tions of  the  method  of  making  them,  together 
with  illustrations,  will  be  found  in  Chapter  V, 
under  Negative  Making. 

It  may  not  be  generally  known  that  photo- 
micrographs were  made  long  before  Da- 
guerre's  discovery  of  photography  itself,  in 
fact,  about  one  hundred  years  ago.  In  1802 
Thomas  Wedgwood  and  Humphry  Davy  — 
afterwards  the  celebrated  Sir  Humphry — made 
a  number  of  photo-mfcrographs,  or  macro- 
graphs, by  throwing  enlarged  images  of  small 
objects  through  a  solar  microscope  upon  sur- 
faces of  paper  or  white  leather  sensitized  with 


4  THE    A    B    C    OF    PHOTO  -  MICROGRAPHY 

a  solution  of  silver  nitrate,  which  soon  faded 
from  not  being  fixed.  There  is  no  record  of 
any  further  advances  in  this  direction  until 
1837,  when  the  Rev.  J.  B.  Reade  obtained  a 
series  of  very  satisfactory  photo-micrographs 
of  insect  and  vegetable  preparations  on  paper 
sensitized  with  an  infusion  of  galls,  table  salt 
and  silver  nitrate.  These  prints  proved  to  be 
permanent  and  of  such  excellent  quality  that 
a  ready  sale  was  found  for  them.  The  optical 
work  was  done  with  the  solar  microscope. 
After  Daguerre's  discovery  of  the  photo- 
graphic process  to  which  his  name  was  given, 
most  excellent  pictures  of  microscopic  objects 
were  made  by  it,  the  oxyhydrogen  light  being 
used  as  the  radiant  for  the  first  time  of  which 
we  have  any  record.  A  little  later  Dr.  Donne, 
of  Paris,  issued  a  work  on  microscopical  anat- 
omy, illustrated  by  photo-micrographs,  taken 
on  daguerreotype  plates  and  chemically  etched 
so  that  they  could  be  printed  from  in  ink. 
Their  excellence  was  marked,  and  they  were 
probably  the  first  photo-micrographs  ever 
published  as  book  illustrations. 

From  that  time  —  more  than  a  half  century 
ago  —  there  has  been  continual  progress  in 
the  art,  until  it  has  reached  an  excellence  un- 
dreamed of,  and  is  universally  in  use  the  world 


INTRODUCTORY 


rover  by  advanced  workers  in  most  branches 
of  science.  It  received  its  first,  and  probably 
greatest  advance,  through  the  labors  of  our 
own  Dr.  J.  J.  Woodward,  of  the  Army  Med- 
ical Museum  in  Washington,  whose  fame  was 
and  is  world-wide.  His  work  in  some  directions 
has  never  been  excelled,  although  it  antedated 
homogeneous  and  apochromatic  objectives, 
gelatine  dry  plates  and  other  appliances  now 
so  common  and  thought  to  be  indispensable 
for  high-class  work.  Dr.  Maddox,  of  Eng- 
land, recently  deceased,  gave  throughout  a 
notable  career  of  more  than  half  a  century, 
a  wonderful  amount  of  help  to  all  workers  in 
photo-micrography.  By  the  aid  of  the  half- 
tone engraving  process,  faithful  and  beautiful 
reproductions  are  furnished  at  a  nominal  cost, 
and  it  may  be  confidently  predicted  that  here- 
after no  work  dealing  with  any  subject  requir- 
ing the  aid  of  a  microscope  will  be  published 
without  being  copiously  illustrated  by  photo- 
micrographs, reproduced  through  the  half-tone 
processes;  most  likely  in  trichrometry. 

For  many  years  I  have  been  fully  convinced 
of  the  importance  of  photo-micrography  in 
educational  interests,^  and  the  trend  of  thought 
and  action  in  that  direction  seems  to  more 
than   justify   my  opinions.     In    some    of   the 


O  THE    A    B    C    OF    PHOTO  -  MICROGRAPHY 

high  schools  of  New  York  city  they  are  used 
to  the  extent  of  several  thousand  prints; 
mostly  thus  far  in  illustrating  animal  his- 
tology. Professor  Peabody  employs  them  in 
his  classes  for  comparison  by  the  students 
with  the  same  subjects  under  the  microscope, 
finding  them  to  be  of  the  greatest  service.  He 
has  lately  published  an  interesting  sketch  of 
this  work.  As  lantern  slides  for  use  on  the 
screen  before  large  classes,  their  importance 
has  long  since  been  fully  established.  It  is 
useless  for  me  to  urge  a  point  already  con- 
ceded by  many  who  wholly  ignored  it  less 
than  a  decade  ago,  and  it  therefore  only  re- 
mains to  say  a  few  words  as  to  the  scope  of 
this  little  book  and  the  reasons  for  its  being. 

The  latter  are  my  firm  conviction  that  every 
student  should,  in  these  days  of  universal  ama- 
teur photography,  be  able  to  do  good  photo- 
micrography as  well  as  to  push  the  button  of 
a  kodak,  and  the  knowledge  that  no  work  on 
the  subject  which  would  teach  him  the  ABC 
of  it  is  at  present  in  existence.  Whether  I 
have  succeeded  in  writing  such,  time  must 
make  manifest.  The  work  is  wholly  original; 
there  are  neither  paste  nor  scissors  in  its  com- 
position. Having  carved  what  little  I  know 
of  the  subject  out  of  actual  experience,  I  have 


INTRODUCTORY  7 

endeavored  to  impart  the  same  to  others  in 
the  simplest  manner  possible,  and  thus  save 
them,  perhaps,  many  an  hour  of  work  and 
experimenting,  which  I  have  gone  through 
with  unaided.  The  large  standard  works  of 
Sternberg,  Pringle,  Spitta  and  others,  are  too 
learned,  too  scientific,  for  the  beginner,  and 
therefore  of  but  little  use  to  him.  The  smaller 
publications, —  all  English  in  so  far  as  I  know 
—  are  really  of  much  less  use,  being  merely  a 
compilation  of  **say  so's"  without  any  practical 
value.  I  earnestly  hope  such  may  not  be  the 
case  with  the  present  little  work.  It  has  been 
written,  after  several  years'  labor  upon  a  book 
of  much  wider  scope  on  the  same  subject  (yet 
unpublished),  to  fill  a  supposed  want,  which 
the  latter  cannot  do.  It  is  written  in  the  first 
person  as  being  more  familiar  with,  I  trust,  my 
sympathetic  circle  of  readers  than  is  possible 
to  the  impersonal  we.  It  is  sent  forth  with  the 
earnest  hope  that  in  its  perusal  may  be  found 
help  for  some  earnest  beginners  in  the  fascinat- 
ing and  important  art  of  photo-micrography. 
And  it  is  possible  that  among  those  who 
**know  it  all''  there  may  be  a  few  who  will 
gather  a  seed  or  two  of  further  information 
from  the  many  sown  broadcast  throughout  its 
pages. 


CHAPTER    II 

The   Microscope   and   Optical 
Apparatus 

The  primary  essentials  in  photo -microg- 
raphy are  a  microscope  and  a  camera,  or 
their  equivalents.  These  may  be  combined  in 
one  instrument,  as  was  actually  done  in  a  com- 
mercial way  by  the  Atwood  Camera-Micro- 
scope a  number  of  years  ago,  but  long  since 
discarded  **for  good  and  sufficient  reasons." 
There  must  be  a  lens  to  magnify  the  object 
and  project  its  enlarged  image — either  direct 
or  through  an  eye-piece  — upon  the  sensitized 
plate,  which  In  turn  must  be  held  in  position 
to  receive  it  by  a  camera  or  some  contrivance 
answering  the  same  purpose.  Of  these,  the 
microscope  is  the  more  important,  since  with 
no  camera,  however  complete  in  design  and 
workmanship,  can  one  make  even  a  passable 
photo-micrograph,  if  the  optical  portions  of 
his  apparatus, —  the  lenses  or  objectives, —  are 
not  properly  corrected  for  the  work.  Almost 
every  one  may,  at  a  pinch,  construct  some- 
thing that  will  answer  for  a  camera,  but  very 

(8) 


MICROSCOPE    AND    OPTICAL    APPARATUS  9 

few  of  US  can  make  a  microscope ;  hence  this 
indispensable  must  be  purchased,  and  should 
be  selected  with  the  greatest  care.  Its  first 
cost  may  be  whatever  sum  one  chooses  to 
invest  in  it :  after  that,  with  proper  care,  its 
cost  for  maintenance  is  nothing.  The  camera, 
on  the  other  hand,  must  be  continually  sup- 
plied with  food  in  the  shape  of  sensitive  plates. 
Between  the  two,  however,  the  earnest  and 
diligent  worker  will  receive  the  reward  of  his 
labors  in  the  shape  of  more  or  less  perfect 
negatives,  as  his  skill  or  lack  of  it  can 
produce. 

Microscopes  specially  designed  for  photo- 
micrography, of  superb  workmanship  and 
combining  every  improvement  and  device  cal- 
culated to  fit  them  for  the  highest  grade  of 
work,  may  be  had  —  for  a  price.  But  it  is  not 
with  these  we  have  to  deal  in  this  little  book. 
Following  upon  the  lines  indicated  by  its 
title,  I  can  do  no  more  than  simply  refer  to 
them  as  being  procurable  if  wanted  ;  every-day 
instruments  for  busy  workers  must  furnish 
the  materials  for  my  illustrations  of  the  begin- 
nings of  practical  photo-micrography.  The 
optical  requirements  for  microscopical  research 
and  study  in  our  leading  colleges  and  schools 
are  now  so  thoroughly  understood,  and  there 


lO         THE    A    B    C    OF    PHOTO  -  MICROGRAPHY 

is  such  a  unanimity  of  opinion  on  the  subject 
among  teachers  generally,  that  the  microscope 
and  outfit  furnished  the  students  are  prac- 
tically the  same  in  design,  quality  and  cost, 
though  supplied  by  many  different  makers  in 
America  and  Europe. 

The  '^Continental"  form  of  stand  almost 
universally  in  use  had  its  birth  in  Germany, 
but  so  eminently  is  it  adapted  to  the  daily 
work  of  the  student  that  it  has  practically 
superseded  all  others  everywhere.  The  usual 
outfit  consists  of  stand  with  two  objectives,  ^'' 
and  Y';  two  eyepieces  or  oculars  of  the  Huy- 
ghenian  form,  and  an  Abbe  chromatic  substage 
condenser.  To  these  an  excellent  ~i-/'  oil  im- 
mersion objective  is  added  for  bacteriological 
and  high  power  work,  at  a  marvelously  low 
price  for  such  a  lens.  The  instruments  by 
Zeiss  and  Leitz,  of  Germany,  and  the  Bausch 
&  Lomb  Company  in  the  United  States  are 
too  well  known  to  need  more  than  mentioning 
here.  All  of  these  eminent  makers  furnish 
outfits  as  above,  practically  the  same  in  design, 
workmanship,  optical  qualities  and  cost.  Each 
has  some  special  feature  of  its  own,  as  well  as 
special  admirers,  but  it  may  be  safely  said  that 
one  cannot  go  amiss  in  selecting  either  of  these 
makes  for  photo-micrographic  work.     Not  so 


MICROSCOPE    AND    OPTICAL    APPARATUS 


II 


universally  known  as  the  foregoing  are  the 
student's  microscopes  and  outfits  of  the  Spencer 
Lens  Company,  Buffalo,  New  York,  but  which 
are  destined  to  at  least  rival  the  best  of  them 
in  popularity  as  they  become  more  generally 
known.  The  name  of  Spencer  indeed  ante- 
dates all  of  these.  The  first  American  lenses 
(made  by  the  founder  of  the  present  house) 
bore  an  extended  reputation  early  in  the  sec- 
ond half  of  the  last  century.  Having  been 
furnished,  through  the  courtesy  of  its  makers, 
with  an  opportunity  to  examine  and  practically 
test  one  of  these  instruments,  I  can  do  no  less 
than  give  expression  to  the  great  satisfaction 
afforded  me  thereby.  In  design  and  general 
appearance  it  closely  resembles  the  other 
microscopes  of  its  class  already  mentioned. 
The  workmanship  throughout  is  first-class; 
the  fine  adjustment  in  particular  being  ex- 
tremely delicate  in  action  with  great  solidity 
of  construction.  The  compound  body  is  of 
greater  diameter  than  other  stands  of  its  class, 
thus  allowing  a  larger  cone  of  light  to  pass 
than  is  possible  with  the  narrow  German 
tubes, —  a  decided  advantage  in  photo-micro- 
graphy, and  particularly  so  when  the  objec- 
tive is  used  alone  for  projection  without  an 
eyepiece.     The  draw-tube   is   then  to   be  re- 


12  THE    A    B    C    OF    PHOTO  -  MICROGRAPHY 

moved  and  the  wide  body  being  carefully 
blackened  on  the  inside  is  ready  at  once  for 
use  in  this  manner.  Other  makers  might  well 
adopt  the  simple  plan  of  blackening  the  in- 
side of  the  tubes,  but  do  not,  as  a  rule,  seem 
to  have  thought  of  it.  The  aplanatic  eye- 
pieces are  particularly  well  adapted  to  photo- 
graphic work,  being  fully  equal  to  the  projec- 
tion oculars  of  Zeiss  for  the  same  purpose. 
A  mechanical  stage  having  very  smooth  rec- 
tangular motions  may  be  adapted  in  a  moment, 
or  removed  as  readily.  The  objectives  are 
remarkably  good,  indeed  the  -h  oil  immersion 
is  the  best  lens  for  photographing  bacteria 
in  tissues  that  I  have  ever  used.  The  lower 
powers  are  equally  excellent.  The  frontispiece 
and  Figures  7  and  20  were  made  with  them. 
Larger  and  more  elaborate  microscope 
stands  are,  of  course,  to  be  had  from  all 
these  makers  (some  of  them  specially  designed 
for  photo-micrography)  up  to  the  most  per- 
fect and  costly  instrument  by  Zeiss  for  that 
purpose,  but  it  is  not  within  the  scope  of  this 
elementary  book  to  do  more  than  mention 
them.  I  may  say,  however,  that  aside  from 
their  greater  and  special  conveniences  no  bet- 
ter work  can  be  obtained  with  them  from  any 
given  objective  than  is  possible  with  the  more 


MICROSCOPE    AND    OPTICAL    APPARATUS         1 3 

simple  and  greatly  cheaper  stands  already  men- 
tioned. If  the  possessor  of  these  but  put 
his  heart  into  the  work  and  make  the  best 
use  of  his  tools,  he  can  depend  upon  results 
which  will  compare  favorably  with  any,  no 
matter  what  microscope  they  may  have  been 
made  with. 

A  Bulls-eye  condensing  lens  mounted  on 
stand,  with  universal  movements,  will  be  neces- 
sary for  the  illumination  of  opaque  objects, 
and  for  throwing  partially  parallel  rays  upon 
the  substage  condenser.  The  latter  should 
be  achromatic  and  provided  with  either  iris 
diaphragms  or  a  series  of  stops.  The  usual 
form  of  chromatic  Abbe  condenser,  supplied 
with  all  of  the  microscopes  I  have  named,  is 
not  suitable  for  photo-micrography,  if  the 
best  work  is  expected;  indeed,  for  critical 
lighting  and  resolution  it  is  utterly  useless. 
It  can  be  made  to  answer  fairly  well  with 
medium  powers,  but  I  would  strongly  advise 
that  it  be  discarded  altogether  when  purchas- 
ing a  stand,  and  an  achromatic  form  procured 
at  the  outset.  A  suitable  lens  for  accurately 
focusing  an  object  upon  the  screen  is  necessary. 
The  most  simple  form  is  that  known  as  a 
three-legged  microscope,  a  double-convex  lens 
mounted  in  a  frame  of  that  description,  with 


14         THE    A    B    C    OF    PHOTO  -  MICROGRAPHY 

a  screw  collar  for  adjusting  its  distance  from 
the  plane  of  focusing  screen.  This  costs  but 
fifty  cents.  A  more  elaborate  and  better 
form,  commonly  known  as  Darlot's  focusing- 
glass,  consists  of  a  compound  lens,  mounted 
in  somewhat  similar  manner,  with  a  clamping 
screw  for  fixing  the  focus  when  adjusted. 

A  much  lower  power  than  the  f^^  objective 
of  these  outfits  is  highly  desirable,  in  fact 
necessary,  for  photographing  many  large  ob- 
jects, opaque  subjects,  etc.  A  most  useful 
lens  is  a  good  2 -inch  properly  corrected 
for  photography.  Unfortunately,  the  limited 
length  of  rack  on  all  the  students'  microscopes 
forbids  the  focusing  of  an  objective  of  so  low 
a  power  unless  it  be  in  a  very  short  mounting, 
which  is  not  possible  for  a  well-corrected 
doublet.  A  feature  of  the  Spencer  microscope 
will  be  found  most  useful  and  essential  in  this 
case.  The  lower  end  of  draw-tube  is  fitted 
with  the  society  screWj  to  which  the  objective 
may  be  attached  and  used  within  the  com- 
pound body,  thus  enabling  one  to  utilize  the 
very  lowest  powers  with  a  small  and  compact 
stand. 

I  have  spoken  of  the  2^^  objective  being 
corrected  for  photography.  It  is  not  perhaps 
generally  known  that  the  corrections  of  the 


MICROSCOPE    AND    OPTICAL    APPARATUS         1 5 

very  best  objectives  were  not  until  within  a 
few  years  at  all  suited  to  photographic  pur- 
poses, there  being  a  decided  difference  be- 
tween their  visual  and  actinic  foci,  for  the 
former  of  which  alone  they  were  corrected^ 
The  consequence  was  that  the  details  of  an 
object  showing  sharp  and  clear  upon  the 
focusing-screen  were  found  to  be  somewhat 
blurred  in  the  negative.  This  applied  only 
to  the  lower  powers,  under  a  Y\  the  difference 
in  the  higher  powers  being  so  slight  as  to 
require  little  or  no  attention.  It  was  then  the 
practice,  after  obtaining  a  sharp  visual  focus 
on  the  screen,  to  withdraw  the  objective  very 
slightly  by  means  of  the  fine  adjustment  screw, 
about  Woo''  for  the  ■^''  or  V;  2W  for  a  Vl 
xfo''  for  the  lY^  objectives.  This  was  not  very 
Satisfactory  at  the  best,  and  a  great  advance 
was  made  when  Wenham  advised  that  a  double 
convex  lens  be  fitted  in  place  of  the  back-stop 
of  the  objective,  one  of  5-inch  focus  for  the 
-^^^  and  f\  and  one  of  8-inch  focus  for  the 
lY^  or  2^^  objectives.  I  have  used  for  many 
years  a  complete  set  of  Beck's  objectives 
from  3^^  to  iV  thus  fitted,  with  entire  satis- 
faction, and  mention  these  facts  here  for  the 
benefit  of  any  who  may  be  in  possession  of 
these    older   lenses.     They  can    readily  have 


1 6  THE    A    B    C    OF    PHOTO  -  MICROGRAPHY 

them  corrected  by  any  reliable  optician.  For- 
tunately, no  such  procedures  are  necessary 
with  lenses  of  the  present  day.  They  are  all 
corrected  with  the  view  of  being  required  for 
photographic  purposes,  and  their  visual  and 
chemical  foci  will  be  found  practically  coin- 
cident. 

The  optical  appliances  thus  far  named  are 
absolutely  essential  for  the  prosecution  of 
photo-micrography  by  transmitted  light  with 
transparent  subjects,  and  by  reflected  light 
with  those  of  an  opaque  nature.  These  com- 
prise the  great  majority  with  which  the  student 
will  have  to  deal,  but  there  are  many  others 
requiring  particular  illumination  to  bring  out 
certain  details  of  structure  which  cannot  be 
done  without  special  optical  apparatus ;  as 
the  polarizer  and  paraboloid  for  dark  field 
effects.  These  will  be  more  fully  detailed  in 
the  chapter  devoted  to  illumination,  but  are 
mentioned  here  in  order  to  bring  them  to 
notice  under  the  head  of  optical  appliances. 
Both  should  form  a  part  of  the  photo-micro- 
graphic  outfit  of  every  serious  worker. 

At  the  moment  of  writing  this  concluding 
paragraph,  I  am  informed  by  my  friend. 
Prof.  M.  L.  Seymour,  of  Los  Angeles,  Cali- 
fornia, that  a  very  valuable   optical   accessory 


MICROSCOPE    AND    OPTICAL    APPARATUS         1 7 

to  the  microscope,  which  he  devised  some 
months  ago,  has  reached  perfection,  and  is 
ready  to  be  placed  on  the  market.  His  note 
was  accompanied  by  photographs  and  descrip- 
tions of  the  apparatus.  It  is  too  late  for 
insertion  in  this  book,  but  full  description, 
with  illustrations  of  work  done  by  it,  will  be 
found  in  my  larger  work  when  issued.  I  can 
only  say  now  that  the  arrangement  is  intended 
to  permit  the  instantaneous  photographing  of 
living  microscopic  forms  and  growing  cells 
whilst  under  observation.  The  magnified 
image  is  in  clear  view  and  at  the  desired  time 
the  simple  pressing  of  a  pneumatic  bulb 
opens  the  shutter,  exposes  the  plate  and 
secures  the  picture.  It  is  simple,  practical 
and   very  valuable. 


CHAPTER    III 

The   Camera   and   Photographic 
Appliances 

A  camera  or  its  equivalent — ^^some  arrange- 
ment by  which  the  sensitive  plate  may  be  held 
in  proper  position  to  receive  the  projected 
image  from  the  microscope  whilst  securely 
protected  from  all  extraneous  light — is  equally 
important  with  the  microscope  itself.  It  may 
be  broadly  stated  at  the  outset  that  any 
camera,  no  matter  what  its  size  or  shape, 
may  be  thus  utilized  provided  it  has  a  focus- 
ing screen;  without  this  it  is  of  no  use  for 
photo-micrographic  purposes.  At  the  same 
time  it  may  also  be  said  that  the  majority  of 
**push  the  button"  cameras  are  but  little  better 
than  makeshifts  for  photo-micrography.  As 
a  rule  their  bellows  are  entirely  too  short  for 
general  usefulness  and  must  be  added  to  in 
some  manner  by  the  user.  This  is  especially 
the  case  with  American  boxes,  though  the 
long  extension  forms  which  most  makers  have 
introduced  recently,  go  a  long  way  toward 
correcting  this  deficiency.     I  would  earnestly 

(i8) 


CAMERA    AND    PHOTOGRAPHIC    APPLIANCES       1 9 

advise  every  one  about  purchasing  a  camera 
for  use  in  photo -micrography  to  provide 
himself  with  one  specially  intended  for  and 
adapted  to  that  purpose.  If  for  any  reason 
this  is  not  feasible  and  he  is  obliged  to  employ 
some  other,  let  him  make  the  best  of  the  situ- 
ation and  adapt  the  box  he  may  happen  to 
have  to  the  end  in  view,  in  the  best  manner 
he  can  contrive.  A  simple  example  of  such 
an  adaptation  must  suffice  at  this  time. 

Having  a  small  camera  with  bellows  exten- 
sion of  about  ten  inches  and  a  student's  micro- 
scope stand  with  joint  for  inclination  of  body, 
I  desired  to  so  adjust  them  quickly  and 
cheaply  as  to  render  them  suitable  for  practi- 
cal work.  It  would  have  been  very  easy  to 
place  each  upon  the  table  top,  with  a  book 
beneath  the  camera  of  proper  thickness  to 
raise  its  center  to  the  level  of  microscope 
eyepiece,  and,  by  the  exercise  of  great  care, 
perchance  secure  a  good  negative  with  no 
further  expenditure  of  time.  But  the  whole 
affair  would  be  so  liable  to  disarrangement  by 
the  slightest  inadvertent  touch  that  it  was  not 
worth  thinking  about.  A  board  some  four 
feet  in  length  by  nine  inches  wide  was  there- 
fore obtained  and  placed  upon  the  table  top. 
To  one  end   of  this    the   camera  was  firmly 


20         THE    A    B    C    OF    PHOTO  -  MICROGRAPHY 

attached,  with  a  second  short  board  beneath 
it  of  proper  thickness  to  raise  it  to  the  height 
of  microscope.  This  in  turn  was  placed  in 
front  of  the  camera  so  that  its  optical  axis 
coincided  with  the  center  of  ground -glass 
focusing  screen,  and  securely  clamped  to  the 
board  or  platform.  The  radiant  —  a  Wels- 
bach  incandescent  mantle,  mounted  on  a  low 
stand,  so  that  it  could  be  freely  moved  about, 
— was  then  placed  some  six  inches  from  the 
substage  condenser  and  a  home-made  stand 
with  holder  carrying  a  color-screen  inserted 
between  the  two.  A  sheet-iron  box,  open  at 
top  and  bottom,  with  glass  front,  was  slipped 
over  the  burner  in  order  to  prevent  the  dis- 
semination of  superfluous  light  in  the  room. 
I  thus  had,  after  a  few  minutes'  work,  a  really 
practical  arrangement  of  microscope  and  cam- 
era capable  of  turning  out  quite  excellent 
photo-micrographs  under  a  considerable  range 
of  amplification.  Reference  to  the  illustration 
(Fig.  i)  will  make  the  details  of  this  arrange- 
ment quite  clear.  Modifications  of  it  may,  of 
course,  be  made  to  suit  all  circumstances,  but 
the  general  ideas  governing  them  are  identical. 
These  comprise  —  presuming  of  course  pos- 
session of  the  necessary  microscope  and  camera 
—  the  arranging  of  them  for  working  together 


CAMERA    AND    PHOTOGRAPHIC    APPLIANCES      21 

in  unison;  absolute  steadiness,  when  so  em- 
ployed, and  the  means  for  placing  them  in 
position  accurately  and  without  loss  of  time. 

It  will  be  vastly  better,  however,  to  obtain  at 
the  outset  a  camera  specially  devised  for  photo- 
micrographic  work,  and  to  have  it  always  in 
readiness  for  immediate  use,  since  it  fre- 
quently happens  during  microscopic  exami- 
nations that  objects  are  found  which  require 
to  be  photographed  or  drawn  at  once.  With 
a  camera  always  ready,  the  microscope  may  be 
very  quickly  attached  and  the  record  made. 
There  are  a  number  of  such  cameras  in  the 
market — some  to  be  used  with  the  microscope 
in  vertical  position  only;  others  are  adapted 
to  the  horizontal  alone,  whilst  a  third  class 
combines  the  two  in  a  single  instrument.^  Of 
the  latter,  the  best  form  I  have  seen  is  one  by 
the  Bausch  &  Lomb  Optical  Company.  Like 
all  of  their  apparatus,  it  is  very  well  made,  is 
equally  firm  and  steady  in  all  positions,  and  sold 
at  a  fairly  moderate  price.  The  accompanying 
illustration  (Fig.  2),  showing  it  horizontally 
inclined,  gives  a  good  idea  of  its  design. 

Probably  the  best  strictly  vertical  photo- 
micrographic  camera  is  that  of  Zeiss  from  the 
world-renowned  works  at  Jena.  A  heavy  tri- 
pod-bar carries  a  column  in  which  a  rod  grad- 


22  THE    A    B    C    OF    PHOTO  -  MICROGRAPHY 

uated  in  centimeters  slides  vertically,  being 
held  at  any  point  by  a  set-screw.  This  rod 
carries  a  cone-shaped  bellows  by  means  of 
two  sleeve  collars,  also  controlled  by  set-screws 
at  any  desired  extension,  and  its  front  is  pro- 
vided with  a  light-tight  connection  between 
the  camera  and  microscope.  As  with  all  work 
emanating  for  the  Zeiss  establishment  it  is 
made  in  the  best  and  most  careful  manner. 

The  upright  camera  by  Leitz  has  had  a 
fairly  large  sale  in  this  country,  principally  in 
schools  and  colleges.  It  is  well  made,  of 
course,  and  is  good — of  its  kind ;  but  its  cost 
($40)  seems  excessive.  The  fact  is  that  a 
horizontal  camera  has  so  many  points  in  its 
favor  that  I  cannot  understand  how  any  one 
could  deliberately  choose  an  upright  type 
when  purchasing,  unless  he  were  entirely 
ignorant  of  the  work  he  was  about  under- 
taking. The  single  point  of  superiority  pos- 
sessed by  the  upright  form  is  found  when  it 
becomes  necessary  to  photograph  objects 
moving  freely  in  a  fluid  medium,  such  as  yeast 
cells,  etc.  In  these  rare  cases  the  object-slide, 
of  course,  lies  flat  and  the  camera  must  be 
held  perpendicularly  above  it.  A  little  ingen- 
uity will  always  enable  one  to  accomplish  this 
in  some  manner,  and  since  an  occasion  for  so 


CAMERA    AND    PHOTOGRAPHIC    APPLIANCES      2^ 

doing  will  not  occur,  perhaps,  in  a  hundred 
or  more  exposures,  it  is  not  worth  while  to 
encumber  one's  self  with  an  otherwise  inferior 
form  of  camera  in  order  to  provide  for  the  in- 
frequent requirement.  An  excellent  method  is 
to  attach  the  camera  to  a  stout  board  fastened 
vertically  to  one  end  of  a  heavy  table,  placing 
the  microscope  beneath  it  on  a  lower  support, 
large  enough  to  carry  a  lamp  as  well.  The 
light  is  to  be  reflected  upward  by  the  mirror, 
as  is  usual  when  using  the  microscope  in  up- 
right position.  DiflFused  daylight  may  be  em- 
ployed for  this  manner  of  working  as  well  as 
that  from  a  lamp  or  other  artificial  radiant. 

Some  twenty  years  ago,  when  no  suitable 
camera  for  photo-micrography  could  be  found 
at  any  dealer's,  I  devised  a  form  which  the 
Scovill  Manufacturing  Company,  of  New  York, 
made  for  me  in  the  most  satisfactory  manner, 
and  which  is  to-day,  after  constant  use  in  all 
these  years,  as  good  as  when  it  left  their 
shop — nay,  better,  in  the  smooth  working  of 
its  various  parts.  A  careful  study  of  the 
illustration  (Fig.  3)  will  serve  to  give  a  fair 
idea  of  its  special  features.  The  bellows  are 
in  two  parts,  with  a  central  box  serving  the 
double  purpose  of  a  support  to  prevent  them 
from  sagging  in  the  middle   and   carrying  a 


24  THE    A    B    C    OF    PHOTO  -  MICROGRAPHY 

lens  for  making  photo-macrographs,  lantern 
slides  or  enlargements  on  bromide  paper. 
This  central  box  and  the  rear  portion  of  the 
camera,  with  the  focusing  screen,  slide  freely 
and  independently  upon  V-shaped  ways,  and 
may  be  firmly  fixed  at  any  desired  point — a 
necessary  feature  in  making  lantern  slides  or 
bromide  enlargements,  the  front  being  im- 
movably attached  to  the  camera-bed.  The 
distance  from  it  to  focusing  screen  with  bel- 
lows fully  extended  is  about  three  feet,  whilst 
the  addition  of  a  second  bellows  (cone- 
shaped),  which  receives  the  eyepiece  of  mi- 
croscope, makes  it  possible  to  have  the  object 
on  stage  of  microscope  fully  five  feet  from 
screen — sufficient  for  almost  any  practical  am- 
plification. This  cone  bellows  may  be  re- 
moved by  simply  turning  a  button  and 
replaced  by  an  ordinary  lens  board  when  it  is 
desired  to  use  the  camera  for  copying,  and 
the  entire  front  can  be  shifted  several  inches 
vertically  or  horizontally.  The  plate-holder  is 
single,  the  plate  being  inserted  at  the  back,  as 
in  the  old  style  of  wet  holders.  This  form  is 
in  every  way  superior  to  any  of  the  double 
holders,  with  the  possible  exception  of  the 
English  book  form,  and  is  especially  adapted 
to  my  method  of    backing  plates — to  be  de- 


PLATE    I 


firmrrrTri 


^^'^^g^^Slg^ily- 


Fig.  3 


PLATE    II 


Fig.  4 
E.  R.  &  C.  camera  and  microscope  arranged  for  use  without  eyepiece 


^.tfJiva;*^!'^/-  Z  ;--U>  -  ,•■ : 


Fig.  5 

E.  R.  &  C.  camera,  slid  back  from  microscope  for  preliminary  arrangement 

of  light  and  object  with  latter 


Fig.  6 
E.  R.  &  C,  camera  and  microscope  arranged  for  high-power  work 


CAMERA    AND    PHOTOGRAPHIC    APPLIANCES      2^ 

scribed  later  on.  It  is  fitted  with  kits  for 
carrying  various  sizes  of  plates,  which  can  be 
used  upright  or  horizontal,  as  the  subject  may 
require.  A  metal  rod  with  milled  head  and 
adjustable  pulley-wheel  attached  to  the  base 
of  camera  frame  furnishes  means  for  manipu- 
lating the  fine  adjustment  when  it  cannot  be 
reached  by  hand. 

This  simple  and  most  efficient  camera  w^as 
early  placed  upon  the  market  by  the  Scovill 
&  Adams  Company,  under  the  somewhat 
lengthy  but  expressive  title  of  **The  Walms- 
ley  Enlarging,  Reducing  and  Copying  Photo- 
micrographic  Camera,"  and  has  met,  I  be- 
lieve, with  a  steadily  increasing  demand.  It  is 
made  in  two  sizes  (6X  x  8%  and  4%x5X), 
each  size  carrying  smaller  plates,  if  desired. 
It  is  perfectly  adapted  to  each  of  several  dif- 
ferent requirements.  For  simple  negative- 
making  in  connection  with  a  microscope  or 
for  copying  engravings,  etc.,  with  a  photo- 
graphic lens,  its  long  bellows  extension,  sim- 
plicity and  smoothness  of  working  leave  lit- 
tle or  nothing  to  be  desired.  In  making  en- 
largements on  bromide  paper  or  lantern  slides 
by  reduction,  it  is  equally  useful,  as  will  be 
detailed  in  the  chapter  devoted  to  those  sub- 
jects.   In  still  another  direction  its  adaptability 


26 


THE    A    B    C    OF    PHOTO  -  MICROGRAPHY 


to  a  purpose  will  be  found  equally  satisfac- 
tory. I  refer  to  the  photographing  under  very 
low  amplifications  (less  than  ten  diameters) ,  of 
macroscopic  objects  too  large  for  the  field  of  an 
ordinary  microscope  objective, —  to  which  I 
have  ventured  to  give  the  name  of  photo-macro- 
graphy,  and  to  the  pictures  thus  made,  that  of 
photo-macrographs.  Full  details  of  the  process 
will  be  found  in  Chapter  V  on  Negative  Mak- 
ing. Illustrations  of  this  camera  in  connection 
with  my  special  microscope  stand  are  given  in 
Figures  4,  5  and  6. 

In  the  preceding  chapter  I  have  endeav- 
ored to  give  clearly  and  briefly  as  possible  an 
idea  of  the  optical  apparatus  necessary  for  the 
making  of  a  photo-micrograph,  which  may  be 
said  to  begin  and  end  with  the  microscope, 
since  each  and  every  piece  is  but  an  accessory 
of  this  central  instrument.  Not  so,  however, 
do  we  find  it  in  the  photographic  department 
of  our  pursuit,  for  no  matter  how  indispens- 
able the  camera  may  be,  there  are  other 
appliances  equally  so,  but  which  have  no  con- 
nection with  it,  as  the  optical  accessories  have 
with  the  microscope.  The  first  of  these  neces- 
sities is  a  dark-room  in  which  the  sensitized 
plates  may  be  manipulated  safely,  from  plac- 
ing in  the  holders  to  the  fully  developed  nega- 


CAMERA    AND    PHOTOGRAPHIC    APPLIANCES       27 

tives.  So  universally  is  amateur  photography 
practiced  in  these  latter  days,  that  I  presume 
most  of  my  readers  are  already  acquainted 
with  all  the  details  of  the  purely  photographic 
portion  of  our  subject,  and  that  any  attempt 
at  guidance  in  that  direction  may  seem  to 
them  superfluous,  if  not  presumptuous.  None 
the  less  I  deem  it  best  to  give  a  few  hints 
culled  from  my  own  practical  experiences  of 
many  years.  So  let  us  start  with  the  dark- 
room. 

This  should  be  of  a  good  size,  well  venti- 
lated and  comfortably  warmed  in  winter.  It 
should  be  provided  with  running  water  and 
sink  of  ample  size  for  all  manipulations  so  as 
to  prevent  any  slop  from  spilling  on  the  floor. 
Shelf  room  for  trays,  bottles  and  graduates 
should  be  provided  within  easy  reach  whilst 
a  negative  is  being  developed.  It  should  be 
electrically  lighted  for  comfort,  convenience 
and  freedom  from  vitiation  of  the  air  by  com- 
bustion of  even  the  most  perfect  lamp.  All 
of  these  conveniences  I  enjoyed  for  several 
years,  and  speak  from  experience,  when  I 
emphatically  advise  every  one  who  can  to 
adopt  them.  But  pleasant  as  they  were,  it  is 
fortunate  that  they  are  not  indispensable,  else 
would  my  work  in  this  direction  have  ceased 


28  THE    A    B    C    OF    PHOTO  -  MICROGRAPHY 

some  years  ago,  since  which  time  my  dark- 
room has  consisted  of  a  none-too-roomy  closet, 
lighted  by  a  ruby  lantern  burning  coal-oil, 
and  every  drop  of  water  must  be  carried  up 
and  down  a  flight  of  stairs.  Yet  I  venture  to 
say  the  negatives  made  in  that  closet  are  at 
least  equal  to  any  I  ever  developed  in  the 
old  perfectly  appointed  dark-room,  and  so 
accustomed  have  I  become  to  the  surround- 
ings and  extra  work  made  necessary,  that  the 
aforetime  conveniences  are  never  missed.  So 
take  heart,  all  ye  who  cannot  compass  these, 
and  make  the  best  of  your  environments. 

As  a  dark-room  accessory,  the  ruby  or  de- 
veloping lantern  holds  precedence.  Make  no 
mistake  in  selection  at  the  start.  It  should 
be  of  ample  size  to  avoid  overheating,  which 
volatilizes  the  oil  and  produces  an  offensive 
odor,  as  well  as  a  dangerous  poison,  if  breathed 
for  any  great  length  of  time.  There  are  many 
such  affairs  in  the  shops,  more  or  less  perfect, 
but  I  think  there  can  be  no  two  opinions  as 
to  the  superiority  of  the  Carbutt  lantern,  on 
account  of  its  large  size,  ample  ventilation  and 
facilities  afforded  for  manipulating  the  lamp. 
I  purchased  one  of  the  first  ever  sold,  almost 
twenty  years  ago,  and  it  has  been  in  more  or 
less   continuous  use  ever   since.     A   sheet  of 


CAMERA    AND    PHOTOGRAPHIC    APPLIANCES       29 


ruby  glass  in  front  of  which  may  be  placed 
one  or  more  thicknesses  of  post  paper,  affords 
a  perfectly  safe  light  for  any  plate,  though 
none  should  ever  be  exposed  close  to  the  lan- 
tern, nor  for  a  longer  period  than  is  abso- 
lutely necessary  during  development.  This 
lantern  has  never  emitted  any  unpleasant 
smell,  and  the  secret  of  this  is  that  it  has 
never  been  permitted  to  get  into  a  condi- 
tion for  so  doing.  ** Eternal  vigilance''  alone 
has  been  the  cause  of  its  freedom  from  this 
too-frequent  occurrence,  but  the  same  care 
would  prevent  the  nuisance  with  any  other 
lantern  that  is  fit  to  use  at  all.  The  rules  — 
which  I  never  neglect — are  extremely  simple. 
The  lamp  is  kept  at  all  times  well  filled  with 
the  best  oil,  carefully  wiped  dry,  and  the  wick 
properly  trimmed.  The  lantern  and  chimney 
are  also  carefully  wiped  both  inside  and  out 
with  a  clean,  dry  cloth.  The  flame  is  kept  at 
a  moderate  height  to  avoid  danger  of  smok- 
ing, and  the  lantern  door  is  opened  at  all  per- 
missible times  for  cooling  the  interior.  As 
soon  as  work  is  done,  the  light  is  extin- 
guished, and  the  lamp  removed  from  the  lan- 
tern, which  is  thrown  completely  open  and 
thoroughly  wiped  out  to  remove  any  oil 
which    may    have    been    volatilized    and    con- 


30  THE    A    B    C    OF    PHOTO  -  MICROGRAPHY 

densed  upon  Its  sides  or  top.  If  these  pre- 
cautions are  taken  you  will  never  have  any 
smell  or  trouble  with  the  use  of  oil  in  the 
dark-room  lamp. 

The  trays  for  developing  may  be  of  hard 
rubber  (preferably),  celluloid  or  agate-ware. 
Do  not  touch  papier  mache.  It  looks  very 
nicely  at  first,  but  the  sharp  edges  of  glass 
plates  soon  cut  through  the  varnish  or  enamel, 
and  then  the  life  of  the  tray  is  but  brief. 
Porcelain  is  easily  broken  and  heavy.  Hard 
rubber  is  altogether  the  best.  There  should 
be  at  least  three  graduates,  2-oz.,  4-oz.  and 
8-oz.  For  the  fixing  bath  I  find  on  the  whole 
a  hard  rubber  or  agate-ware  tray  of  8x10 
size,  fitted  with  cover,  to  be  the  most  satisfac- 
tory. The  acid  fixing  bath  (formula  for  com- 
pounding which  is  given  with  most  makes  of 
plates)  is  undoubtedly  the  best,  keeping  clear 
and  clean  until  exhausted.  My  own  formula, 
as  below,  is  recommended ; 

Sodae  hyposulphite 16  ozs. 

Sodae  sulphite 4  ozs. 

Chrome  alum i  oz. 

Sulphuric  acid i  drachm. 

Water 64  ozs. 

As  the  alum  dissolves  very  slowly,  it  should 
be  powdered  in  a  mortar,  or  a  portion  of  the 


CAMERA    AND    PHOTOGRAPHIC    APPLIANCES      3 1 

water  heated,  in  which  it  may  be  dissolved  and 
then  poured  into  the  rest  of  bath.  The  sul- 
phuric acid  must  be  added  quite  slowly.  If 
you  have  no  running  water  or  drain,  thus 
necessitating  the  use  of  a  pail,  do  not  attempt 
the  employment  of  a  wooden  one.  These 
soon  become  foul  and  leaky.  Get  one  of  the 
best  quality  of  fiber  pails;  it  will  last  for 
years,  always  giving  satisfaction.  They  are 
light,  never  leak,  and,  if  occasionally  coated 
with  asphalt  on  the  inside,  are  always  clean 
and  pleasant  to  use.  A  couple  of  folding 
racks  for  drying  plates,  a  few  stirring  rods 
and  a  scale  for  weighing,  with  some  clean  tow- 
els conveniently  hung  by  loops,  will  complete 
the  list  of  absolutely  necessary  dark-room 
appliances,  excepting  the  developers. 

A  most  important  adjunct,  truly,  and  one 
about  which  pages  might  be  written  did  space 
permit.  Since  this  is  not,  however,  possible, 
I  must  be  brief  to  some  extent.  As  a  general 
rule,  I  would  advise  every  one  who  has  had 
some  experience  in  photography,  including  the 
development  of  his  own  plates,  to  use  the  par- 
ticular developer  with  which  he  is  already  ac- 
quainted, in  his  photo-micrographic  work  —  at 
least  until  he  has  mastered  it  sufficiently  to 
permit  experimentation  with  other  agents,  for 


32  THE    A    B    C    OF    PHOTO  -  MICROGRAPHY 

I  believe  there  is  not  a  single  reagent  among 
the  very  many  now  obtainable  which  will  not 
develop  a  properly  exposed  plate  in  a  satisfac- 
tory manner  if  carefully  used.  Of  course 
some  are  better  than  others,  but  all  can  be 
used.  The  developer  should  bring  out  all 
details  to  the  very  finest,  and  it  should  pro- 
duce the  fullest  density  required  without  chok- 
ing or  obliterating  any  of  them.  It  should 
not  produce  chemical  fog  or  stains  under  any 
circumstances,  and  should  not  be  liable  to  any 
considerable  loss  of  density  in  the  fixing  bath. 
Pyrogallol  in  the  hands  of  an  expert  fulfils  all 
of  these  requirements,  but  it  is  so  sure  to 
stain  the  hands  that  few  amateurs  care  to  use 
it  in  these  days  of  cleaner  developers.  The 
combination  of  two  or  more  reagents  possess- 
ing different  qualities  has  been  found  most 
satisfactory.  I  lay  no  claim  to  having  been 
the  first  to  so  employ  them,  but  I  do  claim 
that  so  doing,  in  my  case,  was  the  result  of  an 
original  thought  brought  about  accidentally. 
I  was  experimenting  with  eikonogen  (then  just 
introduced),  finding  it  a  very  energetic  devel- 
oper and  extremely  rapid  as  compared  with 
hydroquinon,  which  I  had  been  using  for  some 
time  with  satisfaction,  but  it  was  impossible  to 
obtain    requisite    density   in   the    negative.     I 


CAMERA    AND    PHOTOGRAPHIC    APPLIANCES      33 

therefore  poured  it  off  from  the  plate  In  de- 
veloping dish,  supposedly  into  an  empty  grad- 
uate, but  really  into  one  containing  hydro- 
quinon  prepared  for  use.  This  mixture  was 
in  turn  flowed  over  the  fully  developed,  but 
very  thin,  negative  in  dish,  and  not  until  the 
rapid  darkening  of  the  plate  became  notice- 
able was  the  mistake  observed.  The  result- 
ant negative  proving  to  be  one  of  the  best 
I  had  ever  made  and  the  compound  developer 
remaining  clear,  I  continued  to  use  it,  and 
from  that  time  to  the  present  always  with 
satisfactory  results.  In  an  article  contributed 
to  Anthony's  International  Annual  for  1891 
I  have  given  a  rather  full  account  of  this 
*'eiko-hydro"  developer,  with  formulae  for 
compounding  in  two  solutions  or  a  single 
one.  For  years,  however,  I  have  used  it  in  the 
powdered  form,  as  this  keeps  indefinitely  and 
is  always  ready  for  quickly  making  a  solution 
of  unvarying  strength.  The  formula  is  as  fol- 
lows : 

NO.    I. 
Eikonogen I  oz. 

Hydroquinone  ..........     1^  oz. 

Mix  very  thoroughly  and  keep  in  a  glass  vessel  with 
screw  top.  An  empty  jar  of  Higgins*  Photo-Mounter 
will  be  found  just  the  thing  for  this  purpose. 


34         THE    A    B    C    OF   PHOTO  -  MICROGRAPHY 

NO.   2. 

Sodium  carbonate,  dried  and  powdered  .    2  ozs. 
'*       sulphite,         "  **  .    I  oz. 

Mix  also  very  thoroughly  and  put  into  a 
similar  jar.  For  developing  a  photo-micro- 
graphic  negative  a  single  solution  is  the  most 
convenient  and  always  reliable.  For  this  pur- 
pose put  about  10  grains  of  No.  i  in  2  ounces 
of  water  and  stir  until  completely  dissolved^ 
then  add  20  grains  of  No.  2  and  a  few  drops 
of  a  10  per  cent  solution  bromide  of  potas- 
sium, again  stirring  thoroughly.  To  avoid 
the  necessity  of  weighing  the  chemicals  every 
time  I  use  two  small  thimbles,  soldered  to 
short  pieces  of  brass  wire,  one  of  which  holds, 
when  evenly  filled,  the  exact  amount  of  No.  i 
powder;  the  other  doing  the  same  with  No.  2. 
This  developer  acts  slowly  but  regularly,  and 
should  be  allowed  to  proceed  until  the  back 
of  the  plate  is  fairly  well  darkened,  as  there  is 
some  loss  of  density  in  the  fixing  bath.  The 
addition  of  a  few  grains  of  metol  will  give 
greater  energy  to  the  developer,  but  I  have 
not  found  any  other  advantage  in  its  employ- 
ment. The  used  mixture  should  not  be  thrown 
away,  but  filtered  into  a  bottle  to  be  used  as 
a  restrainer  instead  of  bromide  with  a  freshly 
made   solution.     It  may  be  used  repeatedly. 


CAMERA    AND    PHOTOGRAPHIC    APPLIANCES      35 

Although  the  sensitized  plates  are  neces- 
sarily developed  in  the  dark-room,  they  are 
not  properly  appliances  of  that  indispensable 
apartment.  In  fact  they  have  no  business 
there,  save  at  the  times  of  being  placed  in 
the  holders  and  development.  They  should 
be  stored  in  a  dry,  well-ventilated  room,  where 
no  deleterious  gases  or  fumes  can  possibly 
gain  access  to  them.  The  too  common  prac- 
tice of  keeping  plates  in  dark-rooms  is  a  very 
frequent  cause  of  fog  and  other  deteriorations 
in  them,  and  the  avoidance  of  so  doing  cannot 
be  too  earnestly  urged. 

As  to  the  plates  themselves.  It  may  be 
broadly  stated  that  any  of  the  numerous 
brands  now  in  the  market  are  capable  of 
furnishing  satisfactory  photo  -  micrographic 
negatives  if  properly  manipulated,  though  not 
equally  so  with  all  classes  of  subjects.  Some 
of  these  require  certain  qualities  not  found 
in  all  plates  for  their  best  rendition.  As  a 
rule,  very  sensitive  emulsions  yield  soft  nega- 
tives; slower  ones  giving  greater  density,  with 
inclination  toward  harshness.  For  the  greater 
part  of  all  microscopical  objects,  orthochro- 
matic  or  isochromatic  ** color-correct"  plates 
are  infinitely  superior  to  all  others.  Indeed 
so  greatly  are  they  better  that  for  a  long  time 


36  THE    A    B    C    OF    PHOTO  -  MICROGRAPHY 

I  have  used  none  others, —  this  after  the  expe- 
riences of  many  years  with  almost  every  sort 
that  were  made  during  that  time.  It  is  un- 
fortunate that  our  American  makers  are  so 
far  behind  their  foreign  rivals  in  this  particu- 
lar branch  of  plate-making.  Here  it  is  pos- 
sible to  procure  those  sensitized  for  yellow 
rays  alone,  whilst  in  Europe  they  are  made  for 
all  portions  of  the  spectrum.  It  is  said  that 
the  Lumiere  Brothers,  of  Lyons,  whose  **color- 
correct"  plates  are  of  world-wide  fame,  is 
about  to  establish  a  branch  of  its  works  in 
this  country,  a  consummation  most  devoutly 
to  be  wished.  Of  American  plates  the  very 
well-known  orthochromatics  of  Carbutt  and 
isochromatics  of  Cramer  are  most  excellent. 
During  the  past  year  I  have  used,  exclusively, 
Forbes'  orthochromatics,  made  in  Rochester, 
New  York  (the  home  of  photography  in  this 
country),  finding  them  so  uniformly  good  in 
every  particular  and  so  moderate  in  cost  that 
there  has  been  no  temptation  to  change  for 
any  other  brand.  In  stating  this  I  would  take 
occasion  to  say  that  I  am  in  no  manner  inter- 
ested in  these  plates  beyond  the  desire  of 
using  the  best  and  cheapest  in  my  own  work, 
and  having  found  what  I  sought,  feel  like 
sharing  this  good  fortune  with  my  neighbors. 


CAMERA    AND    PHOTOGRAPHIC    APPLIANCES      37 

They  are  furnished  in  two  degrees  of  sensi- 
tiveness and  cover  all  demands,  from  the  low- 
est powers  to  the  highest,  equally  well. 

All  plates  used  in  photo-micrographic  work 
should  be  backed.  In  fact  the  advantage  of 
so  doing  is  even  more  marked  than  in  other 
branches  of  photography,  where  it  is  now 
considered  indispensable.  Here  again  our 
foreign  cousins  are  better  served  than  we.  All 
English  plate  makers  furnish  them  ready 
backed  without  extra  cost.  I  believe— but 
cannot  state  positively — that  Carbutt  is  the 
only  American  manufacturer  who  lists  them, 
but  at  an  increased  cost,  and  the  backing, 
though  efficient,  is  so  difficult  to  remove,  and 
makes  such  a  mess  of  the  developer  that  the 
remedy  becomes  almost  as  bad  as  the  disease. 
As  a  consequence  each  one  of  us  must  learn 
to  back  his  own  plates.  A  method  of  doing 
this,  published  in  one  of  the  annuals  some 
years  ago,  is  so  simple,  easy  of  application  and 
perfect  in  results,  that  I  take  pleasure  in 
reproducing  it : 

Put  10  ounces  of  95  per  cent  alcohol  into  a  wide-mouth 
bottle  with  }i  ounce  of  powdered  white  castilc  soap,  for  a 
stock  solution.  Shake  the  bottle  occasionally  until  the 
soap  is  dissolved,  which  may  take  a  week  or  longer.  When 
half  dissolved  it  is  ready  for  use.  Pour  off  2  ounces  and 
filter,  to  which  add  10  grains  each  of  Eryihrosin  and  Aurin^ 


38  THE    A    B    C    OF    PHOTO  -  MICROGRAPHY 

which  will  be  promptly  dissolved.  Paint  backs  of  plates 
with  this  solution,  using  a  flat  camel's  hair  brush.  It  will 
be  nearly  colorless  in  a  red  light,  and  care  should  be 
taken  not  to  expose  the  plate  to  unnecessary  light,  no 
matter  how  safe  this  is  supposed  to  be.  Wipe  off  the 
coating  with  a  wad  of  wet  cotton  wool  before  develop- 
ment, and  rinse  the  whole  plate  carefully  in  a  tray  of  clean 
water. 

An  original  method  of  backing  plates, 
worked  out  some  years  ago,  has  given  me 
such  uniformly  good  results  that  I  no  longer 
hesitate  to  make  it  known.  Others  may  pos- 
sibly have  used  the  same  means ;  if  so,  I  have 
not  heard  of  it.  The  method  is  extremely 
simple.  Procure  some  sheets  of  thin,  dead, 
black  paper,  and  have  them  cut  into  pieces 
slightly  smaller  than  the  plate.  Do  the  same 
with  an  ordinary  sheet  of  white  blotting 
board.  For  use,  dampen  the  blotter,  and  lay 
the  black  paper  in  a  tray  of  water  for  a  mo- 
ment, taking  care  that  it  becomes  wet  through 
on  both  sides,  leaving  no  air  bells  on  the  sur- 
face. All  this  may  be  done  of  course  in  full 
light,  the  balance  in  that  of  the  dark-room. 
Taking  a  plate  from  its  box,  hold  in  the  left 
hand,  back  upward,  and  not  too  near  the  lan- 
tern, no  matter  how  safe  its  light  is  thought 
to  be.  Then,  with  the  right  hand,  lift  the 
wet  paper  from  the  tray,  drain  off  superfluous 


CAMERA    AND    PHOTOGRAPHIC    APPLIANCES      39 

moisture  and  lay  on  the  plate,  smoothing  it 
out  at  the  same  time.  Now  place  the  damp- 
ened blotter  on  top,  pressing  it  down  all  over, 
with  the  hand  first  and  a  soft  dry  towel  as  a 
finish,  holding  the  plate  all  the  while  by  its 
edges,  between  thumb  and  fingers,  and  not 
allowing  the  hand  to  come  in  contact  with  the 
film  surface.  If  your  plate  holder  opens  at 
the  back,  as  with  the  E.  R.  &  C.  camera,  or 
is  of  the  English  book  form,  it  remains  only 
to  lay  the  plate  in  place  and  close  the  holder. 
If  of  any  other  pattern,  you  may  experience 
some  difficulty  in  employing  this  method  of 
backing;  and  there  are  some  to  which  it  is 
quite  inapplicable.  Every  one  attempting  it 
must  ascertain  that  by  trial.  In  all  cases  where 
it  can  be  used,  nothing  is  more  satisfactory. 
It  is  not  an  absolutely  perfect  backing.  With 
the  utmost  care  there  will  probably  be  some 
little  spots  where  a  thin  stratum  of  air  between 
paper  and  glass  prevent  absolute  optical  con- 
tact. But  in  actual  practice,  I  have  found  it 
quite  equal  to  the  most  approved  methods,  in 
results.  It  is  well  to  note,  that  the  plate  should 
be  backed  and  placed  in  the  holder,  after  all 
preliminary  operations  with  microscope  and 
camera  are  completed  ready  for  the  exposure, 
which  must  be  made  whilst  the  paper  is  still  wet. 


40         THE    A    B    C    OF    PHOTO  -  MICROGRAPHY 

And  now  a  ray  of  light  comes  from  the  far 
East,  illuminating  and  making  clear  whatso- 
ever dark  places  my  black  paper  backing 
scheme  may  contain.  In  the  British  Journal 
Photographic  Almanac  for  1902,  I  have  found 
a  short  article  under  the  caption  of  *^Ex  Ori- 
ente  Lux,"  contributed  by  Mr.  George  Ewing, 
of  Calcutta,  which  makes  the  plan  simply  per- 
fect, and  almost  impels  me  to  purchase  a 
Chicago  self-acting  kicking  machine  for  per- 
sonal use  as  a  well -merited  punishment  for 
not  having  thought  of  it  myself.  However,  I 
am  quite  ready  to  take  a  back  seat  and  to 
give  him  thanks  for  a  suggestion  which  has 
given  me  no  end  of  satisfaction  in  its  practical 
application  during  the  past  month  or  two. 
Instead  of  water  he  uses  glycerine  wherewith 
to  coat  the  black  paper — on  one  side  only  — 
which  not  only  furnishes  an  absolutely  perfect 
backing,  but  will  remain  in  perfect  condition 
for  many  days  after  application  to  the  plate. 
Well  may  he  ask  his  **  readers  to  drop  for  a 
moment  caramel,  burnt  sienna,  Indian  ink, 
gum  and  gamboge  and  many  other  messy 
abominations  and  try  a  backing  of  thin  black 
paper  coated  with  glycerine  and  squeegeed  into 
optical  contact  with  the  back  of  the  plate" — 
to  which  I  will  add  that  the  dropping  will  not 


CAMERA    AND    PHOTOGRAPHIC    APPLIANCES      4^ 

be  for  a  moment  only  but  for  the  altogether. 
So  perfect  Is  this  backing  in  practice  that  I 
have  exposed  a  plate  thus  protected  directly 
facing  several  windows,  outside  of  which  the 
sun  was  shining  brilliantly,  for  several  minutes 
without  the  slightest  trace  of  halation  appear- 
ing in  the  negative  on  being  developed.  In 
preparing  the  paper  for  use  I  lay  a  sheet 
slightly  smaller  than  the  plate  upon  a  clean 
table,  pour  a  small  quantity  of  glycerine  in 
the  middle  and  spread  it  evenly  over  the  sur- 
face with  a  finger,  using  a  liberal  quantity,  but 
not  too  much.  Then  place  it  on  the  back  of 
plate  and  squeegee  into  optical  contact.  Strip 
off  before  development.  The  paper  may  be 
used  repeatedly,  adding  a  little  fresh  glycerine 
each  time.  Try  this.  You  will  use  no  other 
backing  ever  after. 


CHAPTER    IV 

The  Radiant  and  Illumination 

One  of  the  most  important  primary  ques- 
tions confronting  the  beginner  in  photo-micro- 
graphy is  what  form  of  radiant  or  illuminant, 
within  his  means,  will  be  the  best  for  practical 
use.  If  he  be  in  a  position  to  choose  whatever 
he  likes,  then  a  considerable  range  of  light 
sources  is  open  to  him.  First  and  by  far  the 
best  is  that  of  direct  sunlight,  regulated  and 
controlled  by  means  of  a  heliostat.  This  is 
the  purest  and  most  actinic  of  all  radiants, 
making  possible  the  very  shortest  exposures 
and  yielding  negatives  —  all  other  conditions 
being  favorable  —  of  unsurpassed  brilliance 
and  perfection.  In  this  country,  blessed  with 
so  many  days  of  sunshine,  it  is  for  the  day 
worker  a  very  certain  and  reliable  radiant ;  in 
others — England,  for  example — sunny  days 
are  so  rare  as  to  practically  debar  it  from  use. 
It  is  not  within  the  scope  of  the  present  work 
to  do  more  than  refer  to  its  preeminent  merit, 
and  to  advise  those  who  possibly  can  employ 
its  perfect  rays  to  do  so.     Diffused  daylight  is 

(42) 


THE    RADIANT    AND    ILLUMINATION  43 

also  a  good  source  of  illumination,  but  so  un- 
certain in  its  intensity  at  different  hours  of  the 
day  during  the  varying  seasons  as  to  render 
its  employment  somewhat  difficult  and  unsatis- 
factory. Since,  in  common  with  direct  sun- 
light, its  use  is  confined  to  daytime,  the  night 
worker  cannot  employ  either,  but  is  obliged 
to  look  for  some  artificial  source  for  his  light. 

Fortunately  these  are  numerous  enough  to 
suit  his  circumstances  or  convenience,  what- 
ever they  may  be.  First  and  most  important, 
in  fact  rivaling  the  direct  rays  of  the  sun,  is 
the  electric  arc  light,  the  current  for  supply- 
ing which  is  now  so  universally  available  that 
few  are  debarred  from  use  of  it,  should  they 
so  elect.  Nor  is  the  question  of  cost  a  very 
serious  one  any  longer.  A  hand-feed  lamp  — 
very  good — may  be  purchased  for  a  very  mod- 
erate sum.  The  cost  of  installation  is  not 
large  and  that  of  maintenance  equally  incon- 
siderable. The  light  is  steady,  brilliant  and 
highly  actinic,  permitting  exposures  approxi- 
mating in  briefness  to  those  possible  with  sun- 
light. I  would  advise  every  one  to  whom  it 
may  be  available  to  look  carefully  into  this 
source  of  illumination  when  arranging  for  an 
outfit. 

The  rays  of  burning  magnesium  are  proba- 


44         THE    A    B    C    OF    PHOTO  -  MICROGRAPHY 

bly  the  most  highly  actinic  of  any  artificial 
light,  but  the  smoke  and  dust  accompanying 
its  combustion,  together  with  the  compara- 
tively high  cost  of  the  material,  preclude  its 
general  use  where  much  work  has  to  be  done. 
Special  means  may  be  devised  for  disposing  of 
the  fumes  and  dust,  but,  on  the  whole,  burn- 
ing magnesium  as  a  radiant  is  not  likely  to  be- 
come very  useful  in  continuous  work. 

The  lime  light  seems  to  be  the  most  com- 
mon form  of  radiant  in  England  for  photo- 
micrography. This  is  doubtless  due  to  greater 
facilities  for  procuring  the  necessary  oxygen 
and  hydrogen  gases  aflForded  in  that  country, 
together  with  correspondingly  lesser  ones  for 
obtaining  the  electric  current  than  prevail  in 
the  United  States.  The  light  is  highly  actinic, 
very  intense,  and  capable  of  doing  rapid  and 
excellent  work,  but  its  management  is  vastly 
more  complicated  and  troublesome  than  that 
of  the  electric  arc.  It  is,  possibly,  used  to 
some  extent  in  this  country,  but  I  do  not  know 
of  any  one  so  doing. 

In  my  estimation  the  most  generally  useful 
radiant  is  acetylene,  **  a  chunk  of  sunlight 
brought  down  to  the  work  table,"  as  some 
one  has  aptly  remarked.  Its  brilliance,  steadi- 
ness, actinic  qualities  and  cheapness  all  recom- 


THE    RADIANT    AND    ILLUMINATION  45 

mend  it  to  the  photo-micrographer.  In  the 
latter  quality  it  rivals  coal  oil.  A  pound  of 
calcic  carbide,  costing  4  cents,  furnishes  me 
with  a  full  supply  of  light  for  a  week's  work. 
Of  course  steady  burning  would  require  more 
material,  but  for  several  hours'  work  per  day 
or  night,  with  a  burner  consuming  A  of  a 
cubic  foot  of  gas  per  hour,  I  find,  as  stated, 
that  one  pound  of  carbide  lasts  a  full  week. 
The  light  is  extremely  actinic  (probably  fully 
equal  to  that  of  the  lime  light) ,  though  its  inten- 
sity is  much  less,  requiring  considerably  longer 
exposures  than  the  latter — vastly  shorter,  how- 
ever, than  those  necessary  with  a  coal  oil  lamp. 
I  have  used  it  almost  exclusively  in  my  work 
for  more  than  five  years,  and  therefore  am  in  a 
position  to  speak  conclusively  as  to  its  merits 
and  capabilities. 

The  Welsbach  incandescent  gas  light  is 
one  of  the  very  best  sources  of  light  for  low 
and  medium  powers,  but  not  well  suited  to 
high  amplifications,  and  utterly  useless  in 
** critical"  illumination,  as  will  be  shown  later 
on.  The  light  is  brilliant,  intense  and  much 
more  actinic  than  that  of  the  best  coal  oil 
flame.  It  is  very  easily  manipulated  and 
almost  universally  available,  as  a  supply  of 
gas  may  be  obtained  in  all  cities  and  towns 


46         THE    A   B   C    OF    PHOTO  -  MICROGRAPHY 

of  any  size  the  world  over.  A  neat  little  fix- 
ture for  its  use  in  photo-micrography  is  sup- 
plied by  the  Welsbach  Company,  and  its  use 
is  fully  recommended  to  those  whose  work  is 
principally  confined  to  low  and  medium  pow- 
ers and  the  photography  of  tissues. 

Last  to  be  named  but  scarcely  least  in  im- 
portance among  radiants  is  the  reliable,  uni- 
versally available  coal  oil  lamp.  It  can  be  ob- 
tained everywhere  the  world  over,  and  its  yel- 
low rays  are  capable  of  making  as  good  nega- 
tives of  most  subjects  as  are  those  from  any 
other  source  of  light  if  properly  utilized  and 
given  sufficient  time.  The  somewhat  feeble 
illumination  and  inordinate  length  of  exposure 
required  when  using  high  powers  are  diffi- 
culties which  cannot  be  fully  eliminated, 
though  they  may  be  lessened  by  careful 
manipulation,  but  the  finished  negatives  will 
compare  favorably  with  those  made  by  any 
other  radiant.  On  the  whole,  this  familiar 
light  may  be  commended  as  being  one  of  the 
most  useful  to  the  photo-micrographer,  not- 
withstanding the  rather  contemptuous  manner 
in  which  it  is  spoken  of  by  the  **  authorities." 

Having  settled  upon  the  radiant,  our  next 
procedure  is  to  determine  the  manner  in  which 
it  must  be  employed  for  the  illumination  of 


THE    RADIANT    AND    ILLUMINATION  4? 

the  object  we  desire  to  photograph.  The  vast 
majority  of  such  specimens  are  transparent, 
requiring  the  rays  of  light  to  be  thrown 
through  them;  this  mode  of  illuminating 
being  termed  transmitted  light.  Others,  again, 
will  not  permit  the  passage  of  light  through 
their  substance  requiring  to  be  shown  by  its 
reflection  from  their  surfaces.  This  is  known 
as  opaque  illumination.  Many  transparent  ob- 
jects are  shown  best  both  as  to  structure  and 
beauty  when  brilliantly  illuminated  on  a  dark 
background,  which  is  effected  by  means  of  a 
paraboloid  or  by  printing  from  a  positive — to 
be  presently  described.  This  is  called  dark 
field  illumination.  Others,  as  many  crystalline 
subjects,  sections  of  minerals,  etc.,  require  the 
use  of  polarized  light  to  properly  display  their 
beauties  and  structural  details.  With  others, 
again,  as  most  of  the  diatoms,  the  lighting 
must  be  more  or  less  oblique  in  order  to  fully 
resolve  their  delicate  markings.  It  will  be 
necessary  to  determine  which  of  these  classes 
an  object  belongs  to  before  commencing  to 
photograph  it.  Examples  of  the  various 
methods  will  be  found  in  the  succeeding 
Chapter  on  Negative  Making,  wherein  I 
have  striven  to  place  practical  processes  be- 
fore my  readers  in  such  simple  but  at  the 


48  THE    A    B    C    OF    PHOTO  -  MICROGRAPHY 

same  time  explicit  manner  as  will  enable  them 
to  follow  to  success.  And  I  would  here  take 
occasion  to  say  that  no  claim  is  made  that 
they  are  the  only  ones  leading  to  that  desired 
end.  Any  others  which  will  produce  the 
same  or  better  results,  must  be  equally  good. 


CHAPTER    V 

Negative   Making 

Photo-micrography  is  usually  divided  into 
three  groups,  designated  low,  medium  and 
high  power  work.  To  these  I  have  taken  the 
liberty  of  adding  a  fourth  group  under  the 
designation  of  photo-macrography^  2l  slight  en- 
largement (less  than  ten  diameters),  of  macro- 
scopic  objects.  The  amplification  of  the  first, 
or  low  power  group,  ranges  from  ten  to  one 
hundred  diameters;  that  of  medium  power, 
between  one  and  five  hundred,  and  the  term 
high  power,  is  applied  to  all  enlargements 
greater  than  the  last  amount.  The  group  of 
photo-macrographs  comprises  all  subjects  that 
do  not  require  to  be  magnified  more  than 
ten  diameters,  which  is  readily  reached  by  a 
good  photographic  lens  and  a  suitable  camera, 
without  the  employment  of  a  microscope  at 
all.  The  wings  of  butterflies,  many  large 
insects,  leaves,  small  flowers  and  a  host  of 
similar  objects,  needing  but  slight  enlarge- 
ments to  make  striking  and  instructive  pic. 
tures,  may  be  named  as  indicating  some  of 

D  (49) 


50         THE    A   B    C    OF    PHOTO  -  MICROGRAPHY 

the  classes  of  subjects  included  in  this  group. 
Low  powers  are  exemplified  by  photographs 
of  insect  eggs,  and  parts  of  their  anatomy, 
sections  of  stems,  seeds,  woods,  leaves,  min- 
erals, etc.  Animal  tissues,  both  normal  and 
diseased,  are  usually  photographed  under 
medium  powers,  which  really  embrace  a  large 
portion  of  the  most  important  work  in  photo- 
micrography. High  powers  are  necessary  for 
germs,  bacteria,  cell  structure,  diatoms,  blood- 
and  pus-corpuscles,  etc.  I  have  endeavored 
in  the  present  chapter  to  carry  my  readers 
through  the  various  processes  involved  in  mak- 
ing negatives  in  each  group  named;  also  to 
give  them  practical  examples  in  illumination 
by  polarized  and  transmitted  light  or  on  a 
dark  field,  of  transparent  objects,  and  by 
reflected  light  of  opaque  ones. 

Low  powers^  transmitted  light.  It  is  more  than 
probable  that  the  beginner's  first  attempt  at 
photo-micrography  will  be  made  with  one  of 
the  various  students'  microscopes  now  in  such 
general  use.  Supposing  this  to  be  the  case,  we 
will  utilize  such  an  outfit  in  my  first  demon- 
stration. The  microscope  which  happens  to 
be  available  at  the  moment  is  one  of  Spencer's 
stands,  furnished  with  two  object-glasses, 
f  and  i,  two  eyepieces  of  the  usual  Huyghe- 


NEGATIVE    MAKING  5^ 

nian  form,  and  an  Abbe  chromatic  sub-stage 
condenser.  The  object  chosen  Is  a  thin,  trans- 
verse section  of  an  echinus  spine — Echinome- 
tra  lucuntur  —  long  esteemed  by  microscopists 
as  a  very  perfect  test  for  flatness  of  field  in  an 
objective  in  addition  to  its  beauty.  The  mi- 
croscope having  been  inclined  to  a  horizontal 
position,  with  the  slide  placed  on  its  stage 
and  secured  by  the  clips,  we  turn  the  mirror 
aside  in  order  to  leave  the  under  surface  of 
the  stage  quite  free  and  unobstructed.  The 
radiant  —  in  this  case  a  Welsbach  burner,  so 
mounted  as  to  bring  its  centre  in  a  line  with 
the  optical  axis  of  the  microscope  —  is  placed 
about  six  inches  from  the  stage.  Upon  look- 
ing through  the  eyepiece  and  bringing  the 
object  into  focus,  we  find  the  illumination  to 
be  somewhat  uneven,  and  not  altogether  satis- 
factory, caused  by  the  presence  of  the  Abbe 
condenser,  which  is  not  well  adapted  to  the 
low  power  (|  inch)  we  are  attempting  to  use. 
Removing  this  from  its  setting  and  closing 
the  stage  iris  diaphragm  somewhat,  the  illumi- 
nation will  be  found  quite  evenly  distributed 
over  the  whole  field — soft,  yet  brilliant.  But 
we  also  discover  that  only  a  fraction  of  the 
object  is  comprised  within  the  field  of  view. 
Manifestly  it  is  impossible  to   photograph  it 


5^         THE    A    B    C    OF    PHOTO  -  MICROGRAPHY 

as  a  whole,  with  this  arrangement.  What  is 
to  be  done?  The  section  is  clearly  small 
enough  to  be  wholly  embraced  by  the  objec- 
tive. It  must  be  the  higher  magnification  and 
narrower  field  of  the  ocular  that  cause  the 
present  trouble.  What  is  to  be  done?  There 
is  no  lower  power  objective  with  the  outfit. 
We  must  make  use  of  what  we  have  or  aban- 
don the  attempt.  We  are  not  going  to  do 
that,  however,  until  all  eflForts  fail.  Perish  the 
thought!  We  will  discard  the  eyepiece  and 
allow  the  objective  alone  to  project  the  image. 
This  was  the  almost  universal  practice  in  for- 
mer days,  and  the  one  used  exclusively  by  Dr. 
J.  J.  Woodward,  whose  work,  as  a  whole,  has 
never  been  excelled.  It  will  not  answer  with 
apochromats,  which  require  the  addition  of  a 
compensating  or  projecting  ocular  to  complete 
their  corrections;  but  the  case  is  different 
with  achromats,  which,  properly  corrected, 
will  give  a  sharper  and  flatter  field,  when  used 
alone  for  projection,  than  in  combination  with 
the  ordinary  Huyghenian  eyepiece.  Spencer's 
aplanatic  oculars,  however,  work  perfectly  with 
them,  and  should  be  used  by  every  one.  But 
to  return.  In  order  to  see  the  object,  after 
removal  of  eyepiece,  the  camera  must  be 
brought  into  action  with  tube  of  microscope 


NEGATIVE    MAKING  53 

inserted  into  its  front  opening  and  the  en- 
trance of  all  extraneous  light  excluded  by 
wrapping  a  piece  of  some  dark  fabric  about 
the  junction,  or  in  any  other  manner  one  may 
decide  upon;  in  this  case  a  focusing  cloth  of 
cotton-velvet  is  used.  We  now  find  that  the 
whole  of  our  specimen  is  included  within  the- 
circle  of  light  seen  on  the  focusing  screen. 
The  illuminated  disc,  however,  is  somewhat 
contracted  and  shows  a  very  bright  spot  of 
light  on  one  portion  of  its  surface  which  inter- 
feres with  the  definition  of  the  image  and 
threatens  to  spoil  the  negative  unless  removed. 
This  is  readily  done  when  its  origin  is  found 
to  be  reflection  from  the  too  bright  interior 
surface  of  the  tube  or  compound  body  of 
microscope.  A  tube  of  velvet  or  dead  black 
paper  inserted  within  the  body  effectually 
cures  this  ** flare  spot"  trouble,  but  unfortu- 
nately contracts  the  already  too  small  diameter 
of  the  tube,  a  defect  held  in  common  by  most 
of  the  modern  students'  form  of  microscopes. 
In  the  Spencer  stand  we  are  using,  this  defect 
has  been  largely  remedied  by  the  employment 
of  an  outer  body  of  unusually  large  diameter, 
from  which  the  sliding  tube  may  be  entirely 
removed,  leaving  one  of  a  very  excellent  size 
for   photographing    an    image    projected    by 


54         THE    A    B    C    OF    PHOTO  -  MICROGRAPHY 

the  objective  alone.  This  tube  having  been 
thoughtfully  blackened  on  the  interior  by  the 
makers,  there  is  no  necessity  for  lining  it  with 
one  of  black  paper  or  velvet.  A  useful  hint 
is  thus  conveyed  to  other  makers,  which  it  is 
to  be  hoped  they  will  not  hesitate  to  improve. 
If  the  microscope,  camera  and  radiant  are 
set  up  so  that  the  optical  axis  runs  straight 
through  the  center  of  each,  as  they  should  be 
and  as  they  are  in  this  case,  the  circle  of  light 
on  the  focusing  screen  will  be  the  same,  though 
the  image  may  not  be  in  its  center.  This  must 
be  effected  by  moving  the  specimen  on  stage 
very  gently  and  'carefully,  since  the  'slightest 
motion  is  greatly  magnified  on  the  screen. 
Here  a  well-made  mechanical  stage  becomes 
most  convenient  and  important,  but  not  hav- 
ing one  at  present  we  must  use  our  fingers  as 
delicately  as  possible.  This  is  not  diflicult 
v/ith  low  powers,  but  requires  considerable 
practice  and  experience  when  the  amplification 
is  high.  The  projected  image  is  now  in  the 
center  of  a  well-lighted  field,  with  the  camera 
extension  sufficiently  short  to  permit  a  ready 
manipulation  of  the  micrometer  focusing  screw 
whilst  examining  it  upon  the  screen.  It  will  be 
found  difficult  to  distinguish  details  sharply  or 
clearly,  owing  to    the  ground-glass  being  too 


NEGATIVE    MAKING  55 

coarse,  and  this  indistinctness  increases  with 
the  magnification.  It  is  simply  impossible  to 
focus  delicate  structures  possessing  much 
detail  upon  so  rough  a  surface.  Recourse 
must  be  had  to  something  else  and  several 
present  themselves  to  our  seeking.  One  is  to 
cement  a  thin  microscopic  cover  glass  with 
Canada  balsam  to  the  ground  surface  of  the 
screen  which  clears  up  that  amount  of  space, 
permitting  very  accurate  focusing  within  its 
limits  by  means  of  a  focusing  glass.  If  this 
be  placed  —  as  is  usually  done — in  the  center 
of  the  screen,  only  that  portion  of  the  object 
visible  through  this  disc  can  be  focused,  and 
very  often  this  will  not  answer  at  all.  A 
remedy  may  be  found  in  the  employment  of 
several  giasses  cemented  to  different  portions 
of  the  screen,  but  this  is  often  as  bad  or  worse 
than  the  disease:  it  is  but  a  makeshift  at  best 
and  we  will  seek  some  other  means  of  over- 
coming the  difficulty.  If  a  sheet  of  thin  plate- 
glass  or  a  gelatine  dry  plate  treated  in  the 
manner  suggested  by  myself  many  years  ago, 
be  substituted  for  the  ground-glass,  either 
will  make  a  screen,  the  surface  of  which  is 
suitable  for  the  most  accurate  focusing  with 
highest  powers,  though  differing  from  each 
other  and  from  the  ground-glass  in  many  par- 


56         THE    A   B    C    OF    PHOTO  -  MICROGRAPHY 

ticulars.  These  may  be  mounted  in  duplicate 
frames  of  the  regular  screen,  or  the  ground 
glass  of  the  latter  can  be  fitted  so  as  to  be 
removable  and  replaced  by  the  others;  the 
former  plan  being  the  preferable  one.  To 
make  the  gelatine  surface-screen  a  dry  plate 
of  suitable  size  should  be  exposed  for  a  briet 
period  to  white  light  and  developed  until 
slightly  grayed  over,  when  it  is  to  be  fixed  in 
the  ordinary  way  and  thoroughly  washed.  It 
may  be  well  to  treat  two  plates  in  this  manner, 
one  of  which  is  to  be  placed  on  a  rack  and 
dried.  The  other  should  be  bleached  in  the 
mercurial  solution  used  for  intensification, 
well  washed  and  dried.  We  have  thus  two 
screens  with  very  fine  surfaces,  one  of  which 
will  show  the  image,  but  rather  faintly,  to  the 
naked  eye,  the  other  requiring  the  aid  of  a 
focusing-glass,  as  does  the  plate-glass  also. 
Provided  with  these  three  screens  in  addition 
to  the  ordinary  one  of  ground-glass  the  photo- 
micrographer  is  prepared  to  successfully  meet 
all  focusing  problems.  In  using  the  gelatine 
screens  that  surface  is,  of  course,  presented 
towards  the  projected  image  and  the  focusing- 
glass  is  applied  to  the  back  as  with  the  one  of 
ground-glass.  This  is  mounted  in  such  man- 
ner as  to  permit  being  focused  through  the 


NEGATIVE    MAKING  57 

screen  upon  the  gelatine  surface  of  its  oppo- 
site side  and  securely  fixed  in  that  position. 
These  lenses  may  be  procured  of  various 
forms  and  prices,  the  cheapest  being  the  well- 
known  three-legged  microscope  costing  fifty 
cents. 

Prior  to  completing  the  final  focusing,  you 
will  notice  that  I  have  placed  a  carrier  holding 
a  color  screen  of  yellowish  green  between  the 
radiant  and  stage,  in  such  manner  as  to  pre- 
vent any  light  other  than  that  passing  through 
it  from  reaching  the  object.  I  then  close  the 
iris  diaphragm  sufficiently  to  exclude  the  flood 
of  light  entering  by  its  full  aperture  in  vol- 
ume sufficient  to  drown  much  of  the  finest 
details  of  the  object.  It  is  a  very  nice  point 
to  determine  the  precise  amount  of  illumina* 
tion  necessary  for  a  given  subject;  to  avoid 
insufficiency  on  the  one  hand  and  harmful  ex- 
cess on  the  other.  Practice  and  experience 
alone  can  teach  this  matter  of  almost  prime 
importance.  And  observe  carefully  when  using 
a  color  screen  that  the  focusing  must  be  done 
through  it.  It  will  not  answer  to  place  it  in 
position  after  the  focusing  has  been  com- 
pleted. 

Having  at  last  carried  my  readers  through 
the  preliminary  processes  of  making  a  nega- 


58         THE    A    B    C    OF    PHOTO  -  MICROGRAPHY 

tive  with  a  low  power  and  without  an  eyepiece 
by  transmitted  light,  we  may  proceed  to  the 
final  and  very  important  stages  of  exposure 
and  development.  The  holder,  in  which  the 
plate  chosen  for  this  negative  (a  Forbes  or- 
thochromatic  S.)  has  already  been  put  in  the 
dark-room,  is  attached  to  the  camera  in  place 
of  the  focusing  screen,  and  an  opaque  card 
inserted  between  the  radiant  and  stage,  to 
cut  off  all  light  from  the  object.  Now  comes 
the  crucial  question,  which  must  be  answered : 
**How  long  shall  the  exposure  be?"  Al- 
though the  plate  allows  a  very  considerable 
latitude  in  this  important  direction,  it  has  its 
limits.  As  a  rule  it  is  better  to  risk  over- 
rather  than  under-exposure,  since  the  former 
may  be  rectified  to  a  considerable  extent  in 
development,  whilst  the  latter  is  remediless. 
From  previous  acquaintance  with  the  sensitive- 
ness of  this  brand  of  plates  and  the  brilliancy 
of  illumination  on  focusing  screen,  I  am  led  to 
the  conclusion  that  the  length  of  exposure,  if 
made  without  the  color  screen,  should  be  three 
seconds,  and  with  it  some  ten  seconds,  as  its 
employment  usually  trebles  the  time  required 
when  the  screen  is  not  used.  Accordingly  the 
slide  is  gently  withdrawn  from  the  holder,  and 
after  a  moment's  pause  to  allow  subsidence  of 


NEGATIVE    MAKING  $9 

all  vibrations,  the  card  screening  light  is  lifted 
and  its  rays  allowed  to  fall  upon  the  object  for 
that  period  of  time,  when  the  card  is  replaced, 
the  dark  slide  returned  to  the  holder,  and  we 
are  ready  for  the  development.  Proceed  with 
me  now  to  the  dark-room,  where  everything 
necessary  for  this  final  act  in  the  birth  of  our 
negative  has  been  prepared  beforehand.  The 
lamp  is  burning  brightly  in  the  large,  well- 
ventilated  lantern  (Carbutt's),  the  door  of 
which  is  standing  open,  and  there  is  no  evi- 
dence to  the  olfactory  nerves  of  the  presence 
of  any  such  evil-smelling  thing  as  coal  oil  in 
the  little  apartment.  The  developer,  eiko- 
hydro,  stands  ready  mixed  in  a  beaker;  the 
acid  fixing  bath  is  equally  prepared  to  do  its 
duty  when  called  upon.  Closing  the  lantern 
door,  we  still  find  the  room  sufficiently  illumi- 
nated to  enable  us  to  see  what  we  are  doing, 
although  the  light  is  screened  through  one 
sheet  each  of  ruby  and  dark  orange  glass  and 
of  post-paper,  which  renders  it  safe  for  ma- 
nipulating the  plate  with  proper  care,  such  as 
screening  it  from  the  direct  rays  and  covering 
the  tray  containing  it  with  cardboard.  I  take 
the  plate  from  its  holder,  place  in  the  tray 
and  cover  with  the  developer  in  a  single  bold 
sweep,  my  back  to  the  light.     Then  the  card- 


60         THE    A    B    C    OF    PHOTO  -  MICROGRAPHY 

board  cover  is  laid  over  it  and  the  develop- 
ment IS  started.  This  generally  begins  within 
a  minute,  proceeding  slowly,  but  regularly,  un- 
til finished.  We  glance  at  the  plate  occasion- 
ally, holding  it  up  to  the  light  and  looking 
through  it  for  a  moment  without  fear  of  fog- 
ging, since  the  danger  of  this  decreases  very 
rapidly  as  development  advances.  This  must 
be  carried  to  a  greater  extent  than  with  most 
classes  of  photographic  work,  as  plucky  nega- 
tives, with  good  contrasts,  are  almost  always 
necessary.  With  hydroquinon  as  the  devel- 
oper, or  a  component  of  it,  as  we  are  now 
using,  the  plate  should  appear  well  darkened 
on  the  back,  as  there  is  always  a  considerable 
loss  of  density  in  the  fixing  bath  when  this  re- 
agent is  used.  Whilst  talking,  the  develop- 
ment has  proceeded  without  halt  and  now 
appears  to  be  complete.  I,  therefore,  pour 
the  solution  off,  and,  having  no  running  water 
In  the  room,  wash  the  plate  very  thoroughly 
in  a  pail  freshly  drawn,  then  place  it  in  the 
fixing  bath  for  clearing,  which  I  allow  ample 
time  for  doing  completely.  It  is  a  great  mis- 
take to  remove  a  negative  from  the  fixing  bath 
too  soon.  It  will  not  do  to  trust  to  its  appar- 
ent fixation;  make  sure  of  it  by  giving  it 
plenty  of  time,  if  you  desire  permanence.    At 


NEGATIVE    MAKING 


6i 


last,  feeling  sure  of  this  important  work  being 
accomplished,  let  us  take  it  from  the  bath, 
rinse  in  water  and  examine.  **A  fine  nega- 
tive," you  exclaim,  and  **  made  by  an  objective 
of  very  perfect  construction,"  is  added  by  all. 
It  is  the  negative  from  which  the  frontispiece 
to  this  book  was  reproduced,  and  I  think  does 
credit  to  all  concerned  in  its  making — the  op- 
tician, the  plate-maker  and  (modestly)  to  the 
photographer.  It  must  now  be  thoroughly 
washed  to  eliminate  every  trace  of  hypo  from 
the  film.  An  hour  or  two  in  running  water, 
when  the  usually  dirty  Philadelphia  fluid  which 
passes  by  that  name  is  at  all  fit  for  use,  will 
suffice  for  this  purpose;  otherwise  numerous 
changes  of  filtered  water  during  many  hours 
are  necessary  to  remove  the  last  traces  of  this 
necessary  but  treacherous  salt.  Then  swab- 
bing oflF  under  the  tap  with  a  tuft  of  cotton- 
wool, a  final  rinse  in  filtered  water  and  placing 
in  a  rack  for  spontaneous  drying  will  complete 
our  negative.  The  latter  process  may  be 
accelerated  by  standing  the  rack  in  a  current 
of  warm,  dry  air,  free  from  dust.  I  would  not 
advise  my  readers  to  adopt  the  following 
directions,  gravely  given  in  a  recent  English 
work  on  photo-micrography  by  an  eminent 
authority. 


62  THE    A    B    C    OF    PHOTO  -  MICROGRAPHY 

**  We  have  had  so  much  trouble  caused  by  inequalities 
in  the  film  produced  by  irregularities  in  the  drying  that 
some  time  ago  we  gave  much  attention  to  the  subject,  and 
seeing  that  now  hardly  any  trouble  in  that  direction  arises, 
we  venture  to  simply  state  how  it  may  be  avoided.  The 
negative  is  placed,  glass  side  downward,  on  a  cloth  and  a 
fine  handkerchief  is  gently  and  neatly  laid  over  the  gelatine 
side.  It  is  smoothly  and  firmly  pressed  with  the  hand  for 
two  or  three  seconds,  which  allows  the  fabric  of  the  hand- 
kerchief to  absorb  all  the  superficial  moisture.  On  raising 
the  handkerchief  it  will  be  found  that  the  gelatine  shows 
distinct  marks  of  the  fabric.  This  is  not  of  the  slightest 
consequence,  for  it  absolutely  and  entirely  dries  out  of  all 
existence.  The  back  must  now  be  carefully  washed, — one 
source  of  trouble  arises  entirely  from  drops  of  moisture 
accumulating  there.  ...  A  ring  of  slightly  melted  gel- 
atine will  be  the  result,  which  it  is  needless  to  say  spoils 
the  picture.  This  is  especially  the  case  when  the  negative 
is  dried  on  a  hot-water  tank,'*  etc.,  etc. 

One  cannot  refrain  from  smiling  at  the 
thought  of  a  negative  treated  in  the  above 
manner  by  the  majority  of  our  energetic 
young    students. 

When  an  eyepiece  is  used  in  making  a  nega- 
tive with  low  powers,  most  of  the  operations 
are  the  same  as  those  just  described.  In 
accordance,  however,  with  my  plan  of  giving 
practical  illustrations  in  a  variety  of  cases  that 
may  confront  my  readers,  I  will  now  ask  them 
to  assist  in  a  little  more  low  power  work.    For 


NEGATIVE    MAKING  6j 

this  purpose  I  have  chosen  a  slide  of  carci- 
noma which  may  be  of  interest  to  all,  and 
certainly  will  be  to  the  medical  men  among 
them  as  an  illustration  of  diseased  tissues.  A 
low  power,  less  than  lOO  diameters,  shows  its 
details  very  well.  I  have,  therefore,  selected 
a  |-inch  objective,  which,  with  the  Spencer 
i-inch  aplanatic  ocular,  gives  just  the  desired 
amplification  with  a  moderate  bellows  exten- 
sion. We  will  use  acetylene  this  time  from  a 
A-foot  burner  as  the  radiant  instead  of  the 
Welsbach  incandescent  mantle,  and  you  will 
notice  I  have  attached  an  achromatic  condenser 
to  the  substage  of  microscope.  The  specimen 
is  placed  on  the  stage  and  the  radiant  (mounted 
on  a  low  movable  stand  like  the  Welsbach)  is 
made  to  occupy  the  same  position  as  the  latter 
in  our  first  experiment.  Looking  into  the 
eyepiece,  the  object  is  now  brought  to  a 
focus,  the  radiant  being  moved  about  until  the 
field  is  evenly  illuminated,  when  the  condenser 
is  racked  forward  or  back  until  an  image  of 
the  flame  is  seen  projected  perpendicularly 
across  the  field  of  view.  If  it  is  not  in  the 
center  the  stand  carrying  the  burner  must  be 
moved  about  until  it  is  so.  We  now  have 
both  object  and  radiant  in  focus  together^ 
really  '* critical"  illumination  which,  however^ 


64  THE    A   B    C    OP    PHOTO  -  MICROGRAPHY 

cannot  be  utilized  with  this  objective  of  low 
aperture;  the  flame  appearing  as  a  brilliant 
line  of  light  running  across  the  field  of  view 
from  top  to  bottom  with  comparatively  dark 
spaces  on  either  side.  There  are  two  reme- 
dies for  this  trouble,  one  in  racking  the  con- 
denser backward  or  forward  until  an  even 
illumination  of  the  field  is  obtained,  the  other 
in  removing  the  radiant  to  some  fifteen'inches 
from  the  microscope  and  interposing  a  buU's- 
€ye  condenser  with  convex  surface  turned  from 
the  light  in  such  manner  as  to  render  the  rays 
fairly  parallel.  Either  plan  is  very  good  and 
satisfactory.  We  choose  the  former  on  this 
occasion  and  find  the  lighting  of  the  field  to 
be  all  we  could  desire.  The  subsequent  mani- 
pulations are  now  about  the  same  as  those  gone 
through  with  in  making  our  first  negative.  The 
color- screen — yellowish  green  as  before — is 
placed  in  position,  light  and  object  centered 
on  ground-glass  screen,  sharp  definition  ob- 
tained with  gelatine  screen  and  focusing  glass, 
plate  holder  attached  loaded  once  more  with  a 
Forbes  orthrochromatic  S,  and  we  are  ready 
for  the  exposure.  How  long  shall  it  be  ?  The 
plate  is  of  same  sensitiveness  as  the  other  but 
the  light  is  more  highly  actinic  than  the  Wels- 
bach.    On  the  other  hand,  the  object  is  stained 


NEGATIVE    MAKING  65 

red  —  a  highly  non-actinic  color  —  the  amplifi- 
cation is  some  three  times  greater  than  before 
and  the  rays  of  light  have  to  pass  through  an 
ocular  which  always  diminishes  their  intensity 
in  a  large  degree.  Clearly  we  must  allow  them 
considerably  more  time  in  which  to  do  their 
work,  say  three  times.  So  we  give  30  seconds 
exposure,  and  upon  treatment  with  the  pre- 
viously used  developer  find  we  have  an  excel- 
lent negative  from  which  the  reproduction 
(Fig.  7)  has  been  made. 

For  the  benefit  of  some  entomological 
friends  who  will  probably  be  among  my  readers, 
we  v/ill  make  one  more  negative  with  a  low 
power;  choosing,  this  time,  that  ever  favorite 
subject,  **the  blow-fly's  tongue,"  which  pre- 
sents in  its  suctorial  tubes  one  of  the  best 
tests  for  a  half  to  one  Inch  objective  that  I 
know  of.  We  will  use  the  same  optical 
arrangement  as  that  in  the  last  example,  ex- 
cepting the  objective,  for  which  I  have  substi- 
tuted one  of  same  power — | — by  Ross.  The 
plate  is  a  Wuestner  orthochromatic ;  the  screen 
dark  yellowish-green  pot-glass,  the  radiant 
acetylene.  Exposure,  30  seconds;  developer, 
hydroquinone.  You  see  the  reproduction  in 
Fig.  8.  Observe  how  beautifully  the  tubes  or 
false  trachea  are  delineated. 


66  THE    A    B    C    OF    PHOTO  -  MICROGRAPHY 

Medium  Powers  by  Transmitted  Light, — There 
Is  but  little  material  difference  in  the  manipu- 
lations between  photo-micrography  with  low 
or  medium  amplifications.  Under  one  hun- 
dred diameters — which  is  generally  termed  low 
power  work — a  substage  condenser  may  fre- 
quently be  dispensed  with  advantageously. 
But  in  using  medium  powers — one  hundred  to 
five  hundred  diameters — it  should  always  be 
employed,  not  only  to  shorten  exposures,  but 
to  insure  the  best  rendition  of  the  object. 
With  high  powers  its  use  is  absolutely  neces- 
sary. It  is  also  requisite  to  provide  some 
means  for  moving  the  fine  adjustment  screw 
when  the  camera  is  extended  so  far  that  it 
cannot  be  reached  by  the  hand  during  exami- 
nation of  object  upon  the  focusing  screen. 
This  may  be  done  by  means  of  a  rod  and 
pulley-wheel,  as  described  on  page  25  and 
shown  in  Figures  4,  5  and  6.  If  this  is  not 
available,  a  series  of  screw-eyes  may  be  ar- 
ranged on  both  sides  of  the  camera  platform, 
through  which  a  fine  cord  (as  a  fishing  line) 
can  be  strung,  passing  around  a  groove  in  the 
periphery  of  the  micrometer  screw  and  kept 
taut  by  means  of  a  small  weight  attached  to 
each  end  hanging  from  rear  of  the  camera 
platform.     A  very  slight  pull  upon  this  cord 


NEGATIVE    MAKING 


67 


from  either  side  will  suffice  to  move  the  ad- 
justment screw  in  the  most  delicate  manner. 
It  is  not  worth  while  to  repeat  the  processes 
already  shown,  but  may  not  be  amiss  to  fol- 
low the  making  of  the  two  negatives  I  have 
chosen  for  illustrations  of  medium  power 
work. 

In  order  that  my  friends,  the  diatomaniacs, 
may  not  be  neglected,  I  have  selected  one  of 
the  beautiful  discoid  forms,  Aulacodiscus  Ore- 
ganus^  for  our  first  attempt  at  somewhat  higher 
magnification  than  the  earlier  ones.  This 
diatom  is  almost  perfectly  flat  in  the  center  of 
its  disc,  but  the  margin  comprises  a  series  of 
processes  considerably  elevated,  which  make  it 
quite  impossible  to  get  the  whole  surface  into 
one  perfect  focus  with  an  objective  of  even 
moderate  power.  We  therefore  have  to  com- 
promise on  the  focusing,  in  order  to  obtain  a 
passable  whole,  and  Ross'  students'  i-inch  seem- 
ing to  combine  a  low  angle  with  excellent  resolv- 
ing powers,  I  have  chosen  it  as  the  objective. 
A  coal  oil  lamp,  in  the  absence  of  something 
better,  must  suffice  for  the  radiant,  and  as  you 
will  see,  I  am  using  the  edge  of  flame  in  con- 
nection with  a  bulFs-eye  condenser,  shown  in 
Figures  4,  5  and  6.  An  Abbe  chromatic  con- 
denser, with  iris  diaphragm,  is  fitted   to  the 


68         THE    A    B    C    OF    PHOTO  -  MICROGRAPHY 

substage,  and  the  ocular  is  a  Huyghenian 
1%-inch.  This  is  not  an  ideal  photo-micro- 
graphic  combination,  but  quite  equal,  no 
doubt,  to  those  with  which  many  workers  will 
have  to  be  content.  Let  us  see  what  we  can 
do  with  it.  The  operations  of  centering  light 
and  object  and  of  focusing,  being  precisely 
the  same  as  those  already  described,  it  is  un- 
necessary to  repeat  them.  The  plate  is  an 
ordinary  landscape  one  of  moderate  speed. 
A  cobalt  blue  screen  renders  the  illumination 
fairly  monochromatic  in  that  actinic  color,  and, 
of  course,  does  not  necessitate  prolonged  ex- 
posure over  that  requisite  for  the  ordinary  yel- 
low rays  of  the  lamp.  Still  it  must  be  con- 
fessed that  the  lighting,  as  seen  on  the  screen, 
is  not  very  brilliant,  and  a  somewhat  lengthy 
exposure  is  deemed  necessary.  We  decide 
upon  five  minutes,  and  it  is  given.  Fortu- 
nately it  is  evening;  there  are  no  passing  ve- 
hicles, and  not  a  tremor  is  perceptible  through- 
out all  that  while.  Now  comes  the  develop- 
ment in  eiko-hydro,  and  we  have  a  negative 
which  I  think  we  need  not  be  ashamed  of,  in 
view  of  the  circumstances  under  which  it  was 
made.  A  reproduction  v/ill  be  seen  in  Fig.  9, 
the  amplification  being  315  diameters. 

A  second  negative  might  as  well  be  made 


NEGATIVE    MAKING  69 

whilst  we  are  working  with  medium  powers, 
and  my  medical  friends  having  assisted  in  pro- 
ducing one  from  diseased  tissue  under  a  low 
power  (Fig.  7),  I  will  now  endeavor  to  photo- 
graph a  normal  one,  requiring  considerably 
greater  amplification,  as  a  further  example. 
The  slide  is  labeled  **  Human  voluntary  mus- 
cle injected."  Under  a  magnification  of  200 
diameters  or  more  the  striations  are  beauti- 
fully shown,  but  it  is  too  great  to  display  the 
injected  arteries  in  a  very  satisfactory  manner. 
We  must  make  the  best  of  the  situation,  how- 
ever, as  it  is  the  striations  of  the  muscular 
fiber  we  are  after.  The  optical  arrangement 
comprises  an  i-inch  of  moderate  angle  by 
Beck's;  Ross'  substage  condenser,  with  me- 
dium cone  of  light,  and  Spencer's  aplanatic 
ocular,  i-inch.  The  radiant  is  acetylene,  the 
plate  a  Carbutt's  slow  orthochromatic,  with  a 
screen  of  yellow  pot  glass.  An  exposure  of 
three  minutes  is  deemed  necessary ;  the  devel- 
oper is  hydroquinon.  A  fine  negative  is  the 
result,  reproduced  in  Fig.  10,  magnified  200 
diameters.  All  of  the  manipulations  are  the 
same  as  those  already  described  under  low 
power  work. 

High  Powers  by  Transmitted  Light. — For  this 
class  of  work  but  little  changes  are  required 


70         THE    A    B    C    OF    PHOTO  -  MICROGRAPHY 

in  any  of  the  procedures  from  those  already 
shown.  The  lighting  must  be  even  more  care- 
fully looked  after  and  the  focusing  is  much 
more  delicate  and  exacting.  But  it  may  be 
truthfully  said  that  one  who  masters  the  art  of 
making  a  good  photo-micrograph  with  low  or 
medium  powers  can  do  as  well  with  the  high- 
est amplifications  if  he  has  the  necessary  ap- 
pliances and  uses  them  carefully.  A  sub- 
stage  condenser  is  among  these,  and  homo- 
geneous oil  immersion  lenses  for  the  greatest 
amplifications.  A  serious  loss  of  light  from 
any  radiant  less  powerful  than  the  electric  arc 
Is  unavoidable,  which  must  be  compensated 
for  as  far  as  possible  by  increased  care  and 
exposures.  The  modern  oil  immersion  objec- 
tives are  a  boon,  indeed,  since  they  utilize 
about  all  the  light  that  enters  them.  If  we  take 
a  student's  iV  oil  immersion,  and  carefully 
study  its  lighting  of  an  object  on  the  screen 
at  say  +1000,  then  replace  it  with  the  best 
obtainable  dry  i,  under  the  same  amplification, 
(obtained  by  increasing  the  camera's  length  or 
by  higher  eyepiecing),  we  will  find  the  illumi- 
nation by  the  former  to  be  greatly  superior 
to  that  of  the  i,  notwithstanding  the  much 
greater  actual  aperture  of  the  latter  lens,  there 
being  no  loss  of  light  from  either  refraction 


NEGATIVE    MAKING  ^l 

or  reflection  with  the  homogenous  objec- 
tive. 

High  powers  are  chiefly  useful  in  bacterio- 
logical work;  for  the  resolution  of  diatoms  and 
other  test  objects ;  in  photographing  blood ;  the 
pus  corpuscles  and  all  subjects  requiring  great 
amplifications.  But  higher  powers  than  are 
absolutely  necessary  should  not  be  used  simply 
to  exhibit  a  specimen  made  big  as  possible. 
Well  and  clearly  shown  under  a  moderate 
magnification  it  would  be  infinitely  more  in- 
structive and  pleasing.  Could  we  see  every- 
thing in  nature  without  a  microscope  we  cer- 
tainly would  not  need  to  use  one.  Let  us 
make  a  couple  of  negatives  of  this  class,  how- 
ever, and  see  what  we  can  do. 

The  first  subject  I  have  chosen  is  a  kary- 
okinetic  figure  in  a  leucocyte  or  white  blood 
corpuscle,  a  rather  rare  specimen,  by  the  way. 
Radiant  and  condenser  are  first  centered  with 
a  low  power,  and  it  will  be  well  to  find  our 
object,  at  the  same  time  bringing  it  and  the 
flame  into  focus  together,  the  latter  appearing 
as  a  brilliant  vertical  line  of  light  in  the  field 
of  view.  Then  removing  this  lens  and  putting 
a  drop  of  cedar  oil  on  the  front  of  a  iV  hom. 
objective  (a  Powell  and  Lealand  Apochromat 
of  1.40  N.A.),  we  attach  latter  to  microscope 


72  THE    A    B    C    OF    PHOTO  -  MICROGRAPHY 

and  carefully  bringing  it  into  focus  upon' the 
object  find  that  the  brilliant  line  of  light,  as 
seen  under  the  lower  power,  has  now  broad- 
ened out,  covering  the  whole  field  of  view, 
giving  us  ^'critical''  illumination,  i.e.,  radiant 
and  object  in  focus  together.  The  substage 
condenser  is  the  same  achromatic  one  we  have 
employed  before  and  we  use  it  v/ith  nearly  full 
aperture ;  this  objective  being  equal  to  almost 
any  cone  of  light  that  may  be  offered  to  it. 
The  same  aplanatic  ocular  is  also  in  place,  so 
that  our  optical  arrangements  are  unchanged, 
save  in  the  objective  and  larger  stop  of  con- 
denser. The  plate  chosen  —  orthochromatic 
of  course  —  is  a  Forbes  slow  L.  The  speci- 
men shows  several  shades  of  red  in  the  stain- 
ing from  a  deep  one  to  delicate  pinkish.  It  is 
evident  that  sufficient  exposure  to  obtain  de- 
tails in  the  dark  karyokinetic  figure  must  in- 
evitably obliterate  the  more  lightly  stained  cor- 
puscles unless  restrained  in  some  manner.  This 
we  do  with  an  acid-green  screen  placed  in  the 
holder  as  shown  in  Figs.  4,  5,  6,  and  having 
found  from  former  experience  that  a  yellowish 
tinge  would  help  by  modifying  the  blue-green 
of  this  screen,  we  add  to  it  a  second  one  of 
picric  acid,  the  holder  being  constructed  to 
carry  several  in  combination  when  necessary. 


NEGATIVE    MAKING  73 

The  remaining  proceedings  are  those  already 
detailed,  the  focusing  being  completed  through 
both  screens.  The  length  of  bellows  exten- 
sion and  double  screens,  have  so  lessened 
brilliance  of  the  acetylene  flame  that  in  con- 
nection with  the  slow  plate  a  somewhat  long 
exposure  is  manifestly  necessary.  Eight 
minutes  are  accordingly  given,  the  plate  being 
developed  with  eiko-hydro.  Result,  a  fine 
negative  at  +825.     Shown  in  Fig.  11. 

Another  example  of  high  power  work,  in 
which  the  amplification  is  pushed  closely  to 
practical  limits  with  either  of  the  radiants  we 
have  been  using,  may  probably  be  given  with 
profit  to  some  of  my  audience.  I  have  chosen 
the  well-known  test  diatom,  Pleurosigma  angii- 
latum  as  the  object  and  will  endeavor  to 
photograph  it,  **  while  you  wait,"  at  3,000  di- 
ameters. We  could  obtain  better  results  by 
making  the  negative  at  1,000  diameters  and 
enlarging  from  this,  for  it  is  a  curious  fact 
that  the  best  work  on  this  diatom  can  be  done 
at  about  the  latter  magnification.  But  since 
many  have  expressed  a  desire  to  see  a  negative 
made  direct  at  a  great  amplification  we  will 
endeavor  to  gratify  them.  Really  there  is  but 
little  difference  between  the  requirements  for 
this  and  the  preceding  example.     The  optical 


74         THE    A    B    C    OF    PHOTO  -  MICROGRAPHY 

arrangements  throughout  are  identical,  the 
increase  in  magnification  being  made  solely  by 
camera  extension  to  about  five  feet,  decreasing 
the  illumination,  but  not  to  so  great  an  extent 
as  might  be  supposed.  Observe  that  in  this 
instance,  as  with  all  others  in  which  an  eye- 
piece is  used,  the  camera  is  detached  from 
microscope  and  slid  back  in  order  that  center- 
ing and  arrangement  of  object  and  illumination 
may  be  done  directly  on  the  microscope  itself 
in  the  same  way  as  ordinary  examinations  are 
made  with  that  instrument.  The  camera  is 
then  attached  and  lighting,  focusing,  etc., 
completed  upon  the  screen.  For  the  present 
exposure  I  will  use  a  rapid  landscape  plate 
—  not  orthochromatic  —  and  the  cobalt  blue 
screen.  An  exposure  of  ninety  seconds,  with 
development  by  hydroquinon,  gives  us  the 
negative  from  which  Fig.  12  was  produced 
at  +3,000. 

Dark  Field  Illumination, — There  are  many 
transparent  subjects  which  may  be  brilliantly 
illuminated  by  pencils  of  light  passing  through 
them  at  an  obliquity  too  great  to  enter  the 
objective  directly,  so  that  they  appear  some- 
what as  opaque  objects  upon  a  black  ground. 
This  is  termed  **dark  field  illumination,"  and 
will  frequently  exhibit   details  not  visible  by 


NEGATIVE    MAKING  75 

ordinary  transmitted  light,  in  addition  to 
greatly  increasing  their  beauty.  It  is  usually 
effected  by  means  of  a  paraboloid  of  glass 
carried  by  the  sub-stage,  which  reflects  to  its 
focus  the  rays  which  fall  upon  its  internal  sur- 
face. It  is  useful  with  objectives  of  moderate 
angle  and  power  only.  I  have  not  succeeded 
very  well  with  any  above  ^^  inch,  but  others 
seem  to  have  done  better.  The  exposure  in 
photographing  is  greatly  lengthened  as  com- 
pared with  that  required  for  the  same  object 
illuminated  by  direct  transmitted  light.  No 
change  is  required  in  the  optical  arrangement 
we  have  used  in  medium  power  work,  except- 
ing substitution  of  a  paraboloid  for  the  sub- 
stage  condenser  then  employed.  By  this 
means  the  negative  of  Fig.  13  was  produced. 
It  is  a  group  of  the  anchors  and  plates  of 
Synapta  (a  small  marine  animal),  in  the  center 
of  which  may  be  seen  a  wheel  of  Chirodota 
violaceUy  belonging  to  the  same  order  of  holo- 
thuridae.  These  are  calcareous,  without  color, 
and  not  conspicuously  brilliant  objects  when 
viewed  by  ordinary  transmitted  light;  but, 
seen  brightly  illuminated  upon  a  black  ground, 
they  are  exceedingly  beautiful,  as  the  print 
well  shows.  In  making  this  negative  the  ob- 
jective was  a  Beck  first-class  f,  without  eye- 


76  THE    A    B    C    OF    PHOTO  -  MICROGRAPHY 

piece.  Radiant,  flat  side  of  coal  oil  flame ;  no 
condenser  of  any  kind;  a  rapid  landscape 
plate,  without  color  screen.  Exposure,  eight 
minutes;  developer,  pyrogalol;  amplification, 
60  diameters. 

My  friend,  Dr.  A.  C.  Mercer,  of  Syracuse, 
N.  Y.,  has  suggested  a  method  of  making 
prints  giving  the  efi^ects  of  direct  dark  field  illu- 
mination from  any  negative  by  ordinary  trans- 
mitted light,  if  the  subject  be  suited  to  this 
treatment.  Details  which  are  brought  out  by 
the  obHque  lighting  of  the  paraboloid  cannot, 
of  course,  be  shown  by  this  method,  but  it  is 
most  useful  in  very  many  instances  and  unlim- 
ited as  to  the  amount  of  permissible  amplifi- 
cation. Fig.  14  is  a  beautiful  example  of  this 
method  of  obtaining  dark  field  efi^ects.  The 
specimen,  one  of  the  beautiful  discoid  diat- 
oms, Heliopeha,  was  first  photographed  by 
transmitted  light  under  an  ampHfication  of 
225  diameters.  From  the  negative  thus  made 
a  positive  was  printed  by  contact  on  a  glass 
plate  of  slow  emulsion,  from  which  in  turn 
the  paper  print  shown  in  the  reproduction 
was  made.  It  speaks  well  for  the  process, 
which  is  particularly  valuable  to  those  who 
have  no  paraboloid  for  direct  work,  as  is  the 
usual    case   with    the    more    modern    micro- 


NEGATIVE    MAKING  77 

scopes.  It  may  be  interesting  to  some  If  I 
briefly  note  the  procedures  in  making  the 
original  negative:  Objective,  a  first-class  -to 
of  moderate  aperture,  by  Beck's;  ocular, 
Spencer's  aplanatic,  i-inch;  Ross'  achromatic 
substage  condenser;  plate,  medium  landscape; 
screen,  cobalt  blue;  radiant,  acetylene;  ex- 
posure, 2%  minutes ;  developer,  eiko-hydro. 

Opaque  Illumination  by  ^fleeted  Light, — As 
already  noted,  the  great  majority  of  micro- 
scopical subjects  are  viewed  by  transmitted 
light,  being  naturally  transparent  or  rendered 
so  by  artificial  means ;  but  a  vast  number  are 
opaque ;  the  surfaces  only  can  be  seen  as  illu- 
minated by  light  reflected  therefrom.  Usu- 
ally these  require  very  low  or  medium  powers 
for  their  rendition ;  in  fact  the  illumination  of 
an  opaque  object  under  high  amplification  is 
impossible,  excepting  with  certain  classes  of 
subjects  and  by  means  of  special  illuminating 
devices.  In  metallography  it  is  a  most  im- 
portant adjunct  in  studying  the  characters  of 
many  metals  and  alloys,  their  polished  surfaces 
being  examined  under  magnifications  from  lOO 
diameters  to  more  than  i,ooo.  In  high  power 
opaque  work  the  objective  is  made  to  be  the 
illuminator  as  well,  either  by  means  of  a  prism 
or  a  disc  of  thin  glass  placed  within  its  mount. 


78  THE    A    B    C    OF    PHOTO  -  MICROGRAPHY 

But  I  can  do  no  more  than  mention  the  pos-^ 
sibility  of  using  high  powers  with  opaque  ob- 
jects at  this  time  and  place.  We  are  dealing 
only  with  the  ordinary  cases  of  every-day 
work.  Such  are  the  examples  shown  in  Figs. 
15  and  16.  The  former  is  from  a  strewn  slide 
of  diatoms,  mounted  dry  on  a  dead-black  back- 
ground, especially  for  examination  by  reflected 
light,  and  it  certainly  is  a  very  beautiful  object 
under  the  microscope — a  beauty  well  repeated 
in  the  photograph.  Attention  is  directed  to  a 
curious  optical  effect  presented  by  this  pic- 
ture. Viewed  with  the  page  in  ordinary  posi- 
tion, many  of  the  discs  look  like  shallow  sau- 
cers containing  other  diatoms  of  smaller  sizes. 
Reverse  the  page  and  they  all  appear  convex, 
with  the  smaller  forms  pressed  into  their  bulg- 
ing surfaces.  This  is  caused  by  the  illuminat- 
ing pencil  of  light  being  projected  obliquely 
across,  thereby  casting  slight  shadows  of  their 
delicate  margins.  Fig.  16,  having  been  made 
with  diffused  daylight  falling  direct  upon  the 
object,  is  nearly  free  from  shadows,  and  shows 
no  change  when  thus  reversed.  The  two 
negatives  were  made  under  the  following  con- 
ditions. Fig.  15:  Objective,  student's  |; 
ocular,  aplanatic  i  inch ;  radiant,  acetylene,  the 
rays  thrown  obliquely  across   surface   of  ob- 


NEGATIVE    MAKING 


79 


ject  by  a  bull's-eye  condenser;  plate,  rapid 
landscape;  exposure,  30  seconds;  developer, 
eiko-hydro;  magnified  53  diameters.  Fig.  16: 
Objective,  Beck's  first-class  iX-inch;  ocular, 
none ;  radiant,  diffused  daylight  falling  upon 
object,  the  camera  being  used  in  upright  po- 
sition; plate,  rapid  landscape;  exposure,  ten 
minutes,  this  apparently  excessive  time  being 
rendered  necessary  by  the  color  of  object  — 
bright  yellow  on  green  background — and  the 
dimness  of  illumination;  developer,  same  as 
preceding;  amplification,  30  diameters.  Vad- 
ium grossularia ;  cluster  cups. 

Polarized  Light,  It  is  a  matter  of  regret  — 
to  me,  at  least  —  that  this  method  of  illumi- 
nation has  fallen  into  such  general  neglect, 
and  that  its  beautiful  effects  and  valuable 
aid  in  the  delineation  of  very  many  struc- 
tures are  utterly  unknown  to  the  majority  of 
students  at  this  day.  A  generation  since,  every 
microscope  was  supplied  with  polarizing  ap- 
paratus almost  as  carefully  as  it  was  with  ob- 
ject glasses.  Now  probably  not  one  student's 
stand  in  a  thousand  can  boast  of  one.  None 
the  less,  the  beauties  it  reveals  may  be  opened 
by  no  other  key,  and  I  confidently  predict  that 
this  formerly  indispensable  adjunct  to  a  com- 
plete microscopical  outfit  will  again  become 


8o 


THE    A    B    C    OF    PHOTO  -  MICROGRAPHY 


popular  as  of  old.  I  cannot,  however,  pass  it 
by  totally  unnoticed,  though  my  remarks  must 
be  limited  in  space.  For  photographic  pur- 
poses especially  (though  this  holds  good  in 
all  other  cases)  both  prisms  —  polarizer  and 
analyzer — should  be  mounted  to  revolve  freely 
in  their  settings,  and  both  should  be  of  largest 
possible  dimensions.  The  lower  prism  in  my 
own  apparatus  measures  i6  mm.  across  its 
shortest  diameter,  admitting  an  immense 
amount  of  light.  The  analyzer  must  be  car- 
ried between  the  objective  and  compound 
body  of  the  microscope,  and  not  above  the 
ocular,  as  was  formerly  a  common  practice, 
since  it  limits  the  field  of  view  very  seriously. 
If  the  construction  of  substage  permit,  the 
polarizing  prism  and  condenser  should  be 
carried  together,  the  latter  in  front,  of  course. 
The  field  of  view  should  be  completely  dark- 
ened by  rotation  of  both  prisms  to  the  proper 
point  before  placing  the  object  upon  the 
stage,  and  a  selenite  should  not  be  used,  ex- 
cepting in  certain  necessary  cases.  The  ex- 
posures must  be  considerably  lengthened,  as 
with  dark  field  and  opaque  illuminations.  Two 
illustrations  of  this  method  in  lighting  are 
given.  The  first  (Fig.  17)  shows  the  large 
starch  grains  of  canna  root.     These,  mounted 


NEGATIVE    MAKING 


8l 


in  Canada  balsam,  are  practically  invisible  un- 
der plain  transmitted  light,  but,  submitted  to 
the  magic  rays  of  the  polariscope,  present  the 
beautiful  picture  seen  in  the  print,  showing 
the  characteristic  black  cross  of  the  starches 
most  superbly.  The  negative  was  made  in 
this  manner :  Objective,  a  Beck  ro  of  moder- 
ate aperture;  ocular,  none;  condenser,  none; 
revolving  diaphragm,  medium-sized  opening; 
radiant,  coal  oil  lamp,  flat  side  of  flame ;  plate, 
rapid  landscape ;  exposure,  2%  minutes ;  de- 
veloper, pyrogallol;  amplification,  no  diame- 
ters. 

The  beautiful  efi^ects  of  polarization  in  the 
illumination  of  crystalline  substances  are  shown 
in  Fig.  1 8,  the  subject  being  the  flower-like 
crystals  of  amygdalin.  These  are  almost  in- 
visible under  ordinary  transmitted  light,  but, 
submitted  to  that  from  the  polariscope,  are 
seen  in  glowing  colors  upon  a  black  ground. 
The  objective  used  in  making  negative  was  a 
Beck  first-class  |,  without  eyepiece  or  con- 
denser. Radiant,  coal  oil,  flat  side  of  flame; 
plate,  a  medium  landscape;  exposure,  9  min- 
utes; developer,  pyrogalol;  amplification,  70 
diameters.  These  two  negatives  were  made 
nearly  twenty  years  ago,  and  are  in  perfect 
condition  at  present. 


82 


THE    A    B    C    OF    PHOTO  -  MICROGRAPHY 


PhotO'tnicrographing  Bacteria,  Bacteriology  is 
SO  distinctive  and  important  a  field  of  micro- 
scopical research  that  I  have  thought  it  well  to 
give  examples  and  some  brief  directions  in  the 
photographic  aspect  of  it  in  a  paragraph  de- 
voted exclusively  to  the  subject.  It  is  usually 
deemed  a  rather  difficult  one,  but  with  proper 
staining  of  the  specimen  and  a  good  oil  im- 
mersion lens,  it  becomes  one  of  the  easiest 
operations  in  high  power  photo-micrography. 
The  best  stainings  for  this  purpose,  in  my 
experience,  are  carbol  fuchsine,  haem-alum, 
gentian  violet  and  Weigert's  and  Gram's 
methods.  Methyl  blue  is  fairly  good  but 
should  be  used  sparingly.  Amplifications  of 
1,000  diameters  are  almost  universally  adopted 
in  the  scientific  world  as  being  sufficiently  high 
to  show  very  clearly  even  the  minutest  forms, 
and  at  the  same  time  quite  within  the  easy 
reach  of  a  student's  microscope  and  iV  oil 
immersion  objective.  A  substage  condenser  is 
indispensable.  The  Abbe  chromatic  form  will 
answer  but  an  achromatic  is  vastly  superior, 
as  by  its  means  '* critical"  illumination  and 
resolution  are  made  practicable.  No  changes 
in  the  optical  arrangements  from  those  already 
described  as  being  necessary  with  high  powers 
need  be  made,  and  it  only  remains  for  me  to 


NEGATIVE    MAKING  83 

detail  the  making  of  each  of  the  four  nega- 
tives reproduced  in  Figs.  19,  20,  21,  22,  to 
complete  my  remarks  on  bacterial  photo- 
micrography. 

Bacillus  tuberculosis  in  sputum.  Fig.  19. 
Objective,  Bausch  and  Lomb's  iV  oil  immer- 
sion, student's  series;  ocular.  No.  4  Huy- 
ghenian,  of  the  same  make;  condenser,  Abbe 
chromatic,  also  of  same  series;  radiant,  acety- 
lene,!^ foot  burner;  plate,  Carbutt  orthochro- 
matic,  23 ;  screen,  yellow  glass ;  exposure,  7 
minutes;  developer,  eiko-hydro;  amplification, 
1,000  diameters. 

Bacillus  anthracis,  spores.  Fig.  20.  Objec- 
tive, Spencer's  iV  hom.  immersion,  student's 
series;  ocular,  aplanatic  i  inch;  condenser, 
Ross'  To  achromatic,  full  cone ;  radiant,  acety- 
lene, A  foot  burner ;  plate,  Forbes'  orthochro- 
matic  S ;  screens  two,  picric  acid  and  napthol 
yellow ;  exposure  3  minutes,  less  than  half  that 
required  for  previous  one  (Fig.  19),  due  to 
greater  sensitiveness  of  plate,  better  lighting 
by  an  achromatic  condenser  and  the  aplanatic 
ocular ;  developer  the  same,  eiko-hydro ;  ampli- 
fication, 1,000  diameters. 

Streptococcus  pyogenes.  Fig.  21.  Objective, 
Powell  and  Leland  -iV  hom.  apochromat  N.  A. 
1.40;  ocular,  condenser,  plate  and  screens  same 


84         THE    A   B    C    OF    PHOTO  -  MICROGRAPHY 

as  in  preceding  example  (Fig.  20);  radiant, 
acetylene  i  foot  burner;  exposure,  i  minute; 
developer  and  amplification  the  same.  Ob- 
serve again  another  great  reduction  in  length 
of  exposure,  due  entirely  to  the  lens  and  its 
very  wide  aperture. 

Bacillus  Trommel'Schladgel.  Fig.  22.  In  this 
final  example  the  optical  arrangements  were 
precisely  those  used  with  the  two  preceding 
ones  (Figs.  20  and  21).  One  screen  only, — 
picric  acid, — was  employed,  an  acetylene  i  foot 
burner  was  the  radiant  and  the  plate  was 
slower,  being  a  Forbes'  orthochromatic  L,  in 
consequence  of  which,  and  the  denser  stain- 
ing of  the  subject,  exposure  was  doubled, — 
2  minutes, —  development  and  amplification 
being  the  same. 

Having  carried  my  readers  through  the 
processes  of  Negative  Making  from  widely 
differing  subjects  and  illumination ;  under  low, 
medium  and  high  magnifications,  it  remains 
only  to  describe  very  briefly  a  method  of 
doing  the  same  with  still  lower  powers  —  less 
than  ten  diameters.  Macrographs  such  pictures 
would  really  be,  and  I  have  ventured  to  coin  a 
word  in  this  connection  and  call  the  process 
PhotO'Macrography.  Before  doing  so,  however, 
I  deem  this  a  fitting  place  in  which  to  give 


NEGATIVE    MAKING  85 

voice  to  a  few  thoughts  which  have  arisen  as 
these  pages  grew  into  being. 

My  earnest  desire  is  to  disclaim  any  inten- 
tion to  impress  upon  my  readers  an  idea  that 
the  processes  I  have  endeavored  to  make 
clear  are  the  only  practical  ones,  and  must  be 
strictly  followed  in  order  to  insure  successful 
results,  which  I  honestly  believe  is  too  gen- 
erally the  case  with  most  English  writers  on 
the  subject.  On  the  contrary,  I  recognize  the 
fact  that  every  true  worker  must  and  will  have 
his  own  methods  leading  to  the  same  results 
as  those  obtained  by  others  through  totally 
different  ones,  for  there  are  many  ways  of 
accomplishing  a  given  end.  Some  will  doubt- 
less regard  the  whole  stuff  as  being  more  or 
less  prolix,  and  possibly  this  may  be  true,  but 
those  who  **know  all  about  it"  can  skip  such 
portions,  which  are  intended  for  the  real  know- 
nothings  desirous  of  getting  a  start  in  the 
rudiments.  I  am  in  receipt  of  many  communi- 
cations from  correspondents  urging  me  to  go 
down  to  the  roots  of  the  matter  and  **give  all 
the  little  points  that  the  other  fellows  have  left 
out."  One  writes:  **It  will  be  well  to  sup- 
pose ignorance  on  the  subject  and  give  the 
methods  as  you  practice  them,  using  scientific 
terms  only  when   necessary,  and  then  clearly 


86 


THE    A    B    C    OF    PHOTO  -  MICROGRAPHY 


explained.    B is  too  much  so  and  many, 

excepting  true  workers,  can't  grasp  all  the 
minutiae.  I  don't  care  to  read  thirty  pages 
for  a  few  points."  This,  from  one  who  is  a 
**true  worker"  himself,  seems  to  cover  the 
point  I  would  make, —  that  I  have  endeavored 
to  explain  the  various  processes  as  I  follow 
them  as  clearly  as  possible  without  making  any 
claim  for  their  being  the  best  or  the  only 
ones  to  be  pursued.  One  thing  I  do  know,  if 
any  **true  worker"  will  take  a  single  one  or  all 
of  the  specimens  which  I  have  enumerated  and 
follow  the  processes  as  given  in  detail,  he  will 
be  able  to  make  at  least  as  good  a  photo- 
micrograph of  each  one  as  is  herewith  repro- 
duced. When  he  has  arrived  at  that  stage  of 
the  work  he  will  be  ready  to  throw  his  mentor 
overboard  and  take  to  sea  in  his  own  boat. 
A  word  or  two  of  advice — begin  with  the 
low  powers  and  work  upward,  looking  for- 
ward all  the  time  and  not  backward.  Aim 
high.  Never  allow  yourself  to  be  entirely 
satisfied  with  your  own  work.  Always  en- 
deavor to  be  your  own  severest  critic. 

Photo-tnacrography.  Worcester  defines  Macro- 
scopic or  Macroscopical  as  **  noting  an  object 
which,  although  comparatively  minute,  is  visi- 
ble to  the  naked  eye  or  to  the  eye  assisted  by 


NEGATIVE    MAKING  87 

a  pocket  lens/' — usually  an  inch  or  more  in 
focus  and  magnifying  less  than  ten  diameters. 
A  delineation  or  picture  of  an  object  thus  en- 
larged would  be  a  macrograph^  and  if  produced 
by  the  aid  of  photography,  why  should  it  not 
be  termed  a  photo-macrograph?  At  all  events 
I  have  chosen  to  coin  that  word  and  to  define 
it  as  a  slightly  enlarged  picture  or  delineation 
of  a  macroscopical  object  produced  by  means 
of  a  lens  and  sensitized  photographic  plate. 
A  few  reproductions  of  such  pictures,  with 
details  of  methods  employed  in  making  them, 
must  bring  to  a  close  this  already  long 
chapter. 

Photo-macrography  is  clearly  beyond  the 
range  of  the  student's  microscope  as  usually 
furnished.  The  initial  magnification  of  its 
lowest  power  (|),  being  about  15  diameters, 
renders  it  impossible.  Nothing  higher  than 
2-inch  or  3-inch  will  answer  for  this  purpose, 
and  very  few  of  these  stands  have  sufficient 
length  of  rack  to  permit  focusing  with  them. 
Some,  as  Spencer's,  have  a  larger  compound 
body  and  draw-tube  fitted  with  the  society 
screw,  so  that  the  objective  may  be  carried 
within  the  main  tube  and  thus  focused.  Such 
stands  answer  measurably  well,  though  still 
restricted  for  practical  use  by  the  smallness  of 


88  THE    A    B    C    OF    PHOTO  -  MICROGRAPHY 

the  tube  limiting  the  projection  of  image  em- 
braced in  the  field  of  the  objective.  Fortu- 
nately, however,  this  class  of  work  is  well 
within  the  scope  of  a  camera  alone,  any  of 
which,  provided  with  a  rectilinear  lens  of 
short  focus  and  sufficient  bellows  extension, 
may  be  utilized  in  its  prosecution,  if  also  fur- 
nished with  a  ground  glass  focusing  screen. 
The  only  difficulty  amounting  to  anything  will 
be  found  in  the  very  short  bellows,  so  usual 
with  American  cameras,  which  cannot  be  ex- 
tended sufficiently  to  reproduce  an  object  at 
full  natural  size,  to  say  nothing  of  enlarging 
it.  If  one  possesses  the  E.,  R.  &  C.  camera 
(Fig.  3),  this  trouble  will  not  worry  him.  The 
cone  bellows  front  may  be  removed,  and  the 
object,  if  transparent,  fitted  in  a  carrier,  so 
that  all  light  entering  the  camera  must  pass 
through  it.  The  lens  is  to  be  attached  to  a 
board  in  middle  section,  through  the  door 
shown  in  illustration,  and  the  camera  turned 
toward  the  source  of  light,  which  may  be  re- 
flected from  the  sky  or  a  cardboard  placed  at 
proper  angle  by  day.  If  night  work  is  neces- 
sary, the  flat  side  of  a  coal  oil  burner,  a  Wels- 
bach  incandescent  mantle  or  acetylene  flame 
with  rays  made  fairly  parallel  by  means  of  a 
bull's-eye  condenser,  are  all  good  and  satisfac- 


NEGATIVE    MAKING  8^ 

tory*  radiants,  the  main  point  consisting  in 
securing  even  illumination.  This  accom- 
plished, the  section  of  camera  carrying  the 
lens  is  pushed  forward  nearly  to  the  front  and 
fastened.  Then  the  rear  section  is  to  be 
moved  forward  or  backward  until  the  object 
is  seen  in  focus  on  the  ground-glass  screen. 
If  smaller  than  is  desired,  the  lens  must  be 
moved  a  little  nearer  to  the  object  and  the  rear 
section  of  camera  farther  from  it;  if  too 
large  these  movements  must  be  reversed  and 
the  operations  continued  until  an  image  of 
required  dimensions  is  projected  on  the  screen 
and  the  final  sharp  focusing  effected  by  gently 
moving  the  screen  section  backward  or  for- 
ward, as  becomes  necessary.  The  object  glass 
or  lens  is  not  to  be  moved  for  this  purpose, 
as  with  a  microscope.  It  is  effected  entirely 
by  the  focusing  screen.  Rectilinear  lenses  of 
3  to  5  inches  focus,  as  usually  furnished  with 
the  smaller  cameras,  are  the  best  for  photo- 
macrography  in  general,  but  those  of  longer 
foci  may  be  used  if  the  bellows  have  sufficient 
extension.  The  focusing  should  be  done  with 
full  opening  of  the  lens,';but  exposures  made 
with  stops  of  fill  or  //32. 

Should  we  not  have  a  camera  embracing  the 
features    of   the   E.   R.  &  C,  some    method 


90  THE    A    B    C    OF    PHOTO  -  MICROGRAPHY 

must  be  found  for  utilizing  whatever  may  be 
at  our  service  In  that  line,  usually  some  form 
of  hand  or  portable  box  with  tripod.  It  must 
be  fitted  with  a  focusing  screen,  and  the  length 
of  bellows  extension  cannot  be  too  great. 
Procure  a  smooth,  flat  board  about  four  feet 
In  length  by  nine  inches  wide,  and  nail  or 
screw  a  strip  of  wood  (say  an  Inch  wide  by 
half  an  inch  thick)  along  both  edges  of  the 
upper  surface  for  Its  entire  length.  A  second 
board,  three  feet  long,  three-quarters  of  an 
inch  thick,  and  of  suitable  width  to  slide 
smoothly  between  the  guiding  strips,  must 
also  be  provided.  To  one  end  of  the  fixed 
or  platform  board  another  piece  of  same 
width  and  a  foot  or  more  long  must  be  at- 
tached at  a  right  angle,  so  as  to  stand  perpen- 
dicularly when  the  platform  rests  on  a  table 
top.  In  this  board  an  opening  (usually 
square),  the  center  of  which  shall  exactly  co- 
incide with  that  of  the  camera  when  in  posi- 
tion on  the  platform,  must  be  cut  and  two  or 
more  spring  clips  similar  to  those  on  stage  of 
microscope  attached,  for  holding  In  place  a 
glass  plate,  cardboard,  etc.,  over  the  opening. 
Now,  if  our  camera  be  one  of  the  long  focus 
folding  or  portable  varieties  so  generally  made 
at  the  present  time,  with   bellows  twenty  or 


NEGATIVE    MAKING  9 1 

more  inches  in  length  and  a  lens  of  not  over 
five  inches  focus,  we  shall  have  quite  plain 
sailing.  Suppose  the  object  to  be  the  wing  of 
a  butterfly  from  one  to  two  inches  in  length, 
mounted  on  a  glass  slip  with  Canada  balsam, 
rendering  it  quite  transparent.  A  piece  of 
thick  cardboard  with  an  opening  in  its  center 
slightly  larger  than  the  object  is  attached  to 
the  front  board  of  the  platform  by  means  of 
the  spring  clips  already  named,  and  the  object 
slide  secured  to  it  by  same  means.  If  day- 
light is  to  be  our  radiant,  the  platform  carry- 
ing camera  must  now  be  placed  upon  a  table 
before  a  window,  with  its  front  facing  the 
light;  and  the  window  should  be  darkened  in 
such  manner  that  none  can  enter  save  that 
which  passes  through  the  object  or  specimen. 
If  this  is  not  practicable,  another  means  of 
preventing  extraneous  light  from  entering  the 
lens  must  be  devised,  and  will  be  explained 
presently.  The  camera  is  now  to  be  attached 
to  the  sliding  board  and  advanced  until  the 
lens  is  within  a  few  inches  of  the  object,  which 
must  be  moved  about  on  its  cardboard  sup- 
port until  seen  squarely  in  center  of  focusing 
screen.  If  not  amplified  sufficiently,  the  lens 
must  be  carried  closer  to  it  and  the  bellows 
extended  further  away,  the  amplification  being 


92  THE    A    B    C    OF    PHOTO  -  MICROGRAPHY 

limited  solely  by  their  length.  If  it  be  found 
too  great,  the  operations  are  to  be  reversed — 
the  lens  removed  farther  from  the  subject  and 
the  bellows  shortened.  The  desired  magnifi- 
cation having  been  attained,  final  focusing  is 
done  by  moving  the  screen  back  or  forth,  and 
for  such  low  powers  the  ground  glass  is  suffi- 
ciently fine  to  do  so  with  the  greatest  accu- 
racy. If  our  room  has  not  been  darkened,  it 
will  be  found  that  a  large  amount  of  light  en- 
tering the  window  falls  upon  the  lens  without 
first  passing  through  the  object.  This  must 
be  cut  off  by  a  cloth  or  some  other  covering 
placed  over  the  space  between  the  two.  A 
stop  or  diaphragm  of  about  //22  must  then  be 
inserted  and  cardboard  or  other  device  placed 
in  front  of  the  object  or  between  object  and 
lens,  as  may  be  found  most  convenient,  to  cut 
off  entrance  of  light  whilst  the  slide  Is  being 
drawn  from  the  holder.  If  the  lens  is  pro- 
vided with  a  time  shutter  so  much  the  better, 
but  cap  exposures  are  not  advisable,  for  fear 
of  disarranging  something.  The  length  of 
exposure  can  only  be  ascertained  by  practice 
and  experiment,  but  something  may  be  learned 
about  it  by  carefully  studying  the  explanations 
as  to  the  making  of  the  four  negatives  herewith 
reproduced.     Should  artifici«al  illumination  be 


NEGATIVE    MAKING 


93 


resorted  to,  the  radiant  must  be  placed  upon 
the  table  in  front  of  camera  and  behind  the 
object,  at  such  a  height  that  its  center  shall 
coincide  with  that  of  the  lens.  The  rays  may 
be  condensed  upon  the  object  by  means  of  a 
bull's-eye  condenser  or  diffused  by  placing  a 
sheet  of  ground  glass  between  the  light  source 
and  object.  The  proper  length  of  exposures 
must  be  learned  by  practice,  but  they  will  be 
somewhat  longer  than  those  required  for  dif- 
fused daylight  illumination. 

Should  our  camera  be  one  of  the  usual 
short  bellows  form  it  will  be  of  little  or  no 
use  in  making  enlargements  or  photo-macro- 
graphs without  certain  modifications.  To 
start  with,  an  upright  board  should  be  at- 
tached to  the  front  end  of  sliding  platform, 
with  a  circular  opening  at  precisely  the  same 
height  as  that  in  camera  front.  The  lens 
flange  of  latter — or  better  a  duplicate  one — 
must  be  fastened  to  this  board  to  carry  the 
lens  instead  of  camera.  If  the  front  of  camera 
is  removable,  so  as  to  admit  all  of  the  rays 
projected  by  the  lens,  the  manipulation  will  be 
very  simple,  for  we  have  the  same  conditions 
as  in  the  last  example:  a  lens  and  focusing 
screen  moving  independently.  The  object 
may   be    centered    and    brought    to    desired 


94 


THE    A    B    C    OF    PHOTO  -  MICROGRAPHY 


dimensions  as  in  that  case,  the  camera  secured 
to  platform  and  final  sharp  focusing  effected. 
Then  the  space  between  lens  board  and 
camera  front  is  to  be  covered  to  exclude 
undesirable  light,  when  the  operations  may 
be  concluded  as  before. 

A  recent  number  of  British  Journal  of 
Photography — that  of  May  lO,  1901 — con- 
tains an  imperfect  description  and  worse  illus- 
trations of  a  portable  camera  for  enlarging 
which  would  seem  to  be  admirably  adapted 
also  to  photo-macrography.  These  convey 
the  idea,  however,  and  it  seems  to  be  so  prac- 
tical and  worthy  of  adoption  that  I  subjoin 
both  description  and  illustrations  as  given  in 
that  journal.  I  have  not  seen  the  instrument, 
but  from  the  well-established  reputation  of  its 
makers,  have  no  doubt  of  its  efficiency. 


^rr:^ 


.t£mia 


Watson  s  Enlari:injj  Apparatus 


**In  the  enlarging  system  shown  by  the 
appended  illustrations,  Messrs.  Watson  have 
combined    simplicity  with    portability.      The 


NEGATIVE    MAKING  g^ 

body  of  the  instrument  is  made  of  mahogany, 
and  the  central  extension  portion  takes  the 
form  of  a  camera  bellows.  By  one  or  two 
easily  controlled  movements  the  enlarger,  when 
not  required  for  use,  may  be  made  to  collapse, 
and  it  is  then  packed  up  within  itself  as  shown 
in  the  second  illustration.  The  quarter-plate 
and  five  by  four  sizes  admit  of  the  negative 
(glass  or  film)  being  enlarged  up  to  8%  by 
6/2  and  lo  by  8,  and  the  half-plate  up  to  I2 
by  lo.  A  lens  is  supplied  with  the  instru- 
ment, or  the  photographer's  own  lens  can  be 
adapted  and  focused.  For  daylight  work,  to 
a  moderate  degree  of  amplification,  this  port- 
able enlarger,  which  has  been  submitted  to 
our  inspection,  should  meet  the  needs  of  a 
very  large  body  of  amateur  photographers." 

Should  the  front  of  our  camera  be  fixed,  the 
instrument  will  be  of  no  use  in  photo-macrog- 
raphy.  We  must  contrive  a  portable  bellows 
or  a  series  of  boxes  sliding  within  each  other 
and  fitted  with  a  focusing  screen  at  one  end 
which  may  be  replaced  by  a  plate-holder,  and 
with  these  make  an  arrangement  for  receiving 
and  utilizing  the  image-bearing  rays  projected 
by  the  lens. 

Four  illustrations  of  photo-macrographs  of  as 
many  widely  differing  subjects  are  given.    The 


96         THE    A   B    C    OF    PHOTO  -  MICROGRAPHY 

following  descriptions  will  show  the  method 
pursued  in  making  each  one  and  may  serve  as 
guides  in  similar  cases.  They  were  all  made 
with  the  E.  R.  &  C.  camera  (Fig.  3)  by  light 
reflected  from  a  western  sky. 

Fig.  23.  Corisa  undulata^  or  Water  Boatman. 
This  is  a  large  insect  of  too  great  size  to  be 
comprised  within  the  field  of  any  ordinary 
microscope  objective,  but  easily  shown  in  that 
of  a  photographic  lens,  which  in  the  present 
case  is  one  of  Beck's  rapid  rectilinears  of  7 
inches  focus,  the  stop  being  fjii.  Plate, 
Forbes'  orthochromatic  L ;  screens  two,  picric 
acid  and  acid-green;  exposure,  80  seconds; 
developer,  eiko- hydro;  amplification,  3% 
diameters. 

Fig.  24.  Transverse  section,  stem  of  Ser- 
jania^  a  tropical  climbing  plant.  This  speci- 
men was  quite  within  the  capacity  of  a  3-inch 
microscope  objective,  but  was  taken  with  a 
photographic  lens  to  show  the  capability  of  the 
latter  in  delineating  microscopic  details  of  the 
cell  structure.  Lens  was  Beck's  5-inch  recti- 
linear of  same  series  as  that  used  in  the  pre- 
ceding example,  with  same  stop,  //22  ;  Forbes' 
orthochromatic  plate,  L;  napthol  yellow  screen, 
exposure,  5  minutes;  amplification,  5  diam- 
eters. 


NEGATIVE    MAKING 


97 


In  Fig.  25  a  female  mosquito,  Anopheles^ 
is  shown.  The  lens  was  the  same  as  the  last, 
with  stop  7/32.  Exposure,  4  seconds;  plate, 
rapid  landscape;  no  screen;  developer,  eiko- 
hydro;  amplification,  3  diameters. 

Fig.  26.  Human  scalp  —  flat  section,  cut- 
ting hairs  transversely.  Lens,  Ross'  con- 
centric 4  inches  focus;  stop,  //22;  plate, 
Forbes'  orthochromatic  S;  screen,  picric  acid; 
exposure,  2  minutes;  developer,  eiko-hydro; 
amplification,  7  diameters. 


CHAPTER  VI 

Printing  Methods  —  Lantern  Slides 

I  fear  the  title  of  this  chapter  may  be  some- 
what misleading,  since  it  is  by  no  means  my 
intention  to  enter  upon  a  description  of  the 
many  printing  processes  open  to  the  photo- 
micrographer.  There  is  not  available  space 
in  this  book  for  the  full  explanation  of  a  tithe 
of  them,  and  the  student  is  referred  to  the 
many  works  on  photographic  matters  for  in- 
formation on  the  subject  in  general;  but  there 
are  some  inklings,  born  of  experience,  which 
I  think  it  well  to  jot  down.  It  may  be 
broadly  stated  that  any  known  printing  pro- 
cess will  yield  good  prints  from  a  photo- 
micrographic  negative,  although  there  is  a 
very  decided  choice  among  them  if  one  looks 
for  the  best  work.  The  old  albumenized  or 
plain  salted  papers,  gelatine  or  chloride  emul- 
sion P.  O.  P.,  of  which  there  is  an  endless 
variety,  carbon  tissue,  platinum  and  bromide 
of  silver  papers,  will  all  give  good  results  if 
properly  used.  But  my  own  preference  is 
decidedly  for  the  Velox  glossy  paper,  which  I 

(98) 


PRINTING    METHODS  — LANTERN    SLIDES  99 

have  used  almost  exclusively  since  its  intro- 
duction, a  number  of  years  ago.  A  shining 
surface  is  detestable  in  a  landscape  print  and 
numerous  other  subjects,  but  it  is  perfectly 
adapted  to  the  delineation  of  a  microscopic 
object,  when  it  possesses  the  peculiar  proper- 
ties which  have  made  Velox  altogether  the 
best  printing  medium  for  this  class  of  work 
that  I  have  ever  seen.  The  most  delicate 
details  are  rendered  with  the  fidelity  of  a 
glass  transparency;  they  are  not  sunk  into 
the  paper,  but  borne  entirely  upon  its  surface. 
The  printing  may  be  done  by  lamp-  or  gas- 
light, with  even  greater  regularity  and  cer- 
tainty than  by  day.  The  development  is  sim- 
ple and  sure ;  there  is  no  toning  to  be  done. 
Pure  whites,  glossy  blacks,  lovely  half-tones, 
are  always  obtainable,  and  the  prints  are 
almost  without  doubt  permanent,  whilst  the 
paper  itself  keeps  indefinitely  previous  to  be- 
ing printed  upon.  All  of  the  operations  may 
be  pursued  in  subdued  daylight  or  by  ordi- 
nary lamp-light.  No  dark-room  is  necessary. 
The  paper  itself  is  so  heavy  as  really  to  re- 
quire no  mounting.  Of  more  than  4,000 
prints  made  three  years  ago  for  a  portion  of 
the  High  schools  of  New  York  city,  not  one 
was   mounted    on   cardboard,  yet   they  have 


100      THE    A    B    C    OF    PHOTO  -  MICROGRAPHY 

been  in  continuous  use  by  classes  of  students 
during  all  the  succeeding  sessions  and  are  in 
good  condition  at  the  present  time.  Finally, 
it  is  no  more  costly  than  any  of  the  ordinary 
papers  that  are  inferior  to  it  for  our  purpose. 
Its  price  is  somewhat  higher  than  these,  but 
this  is  more  than  offset  by  the  cost  of  gold 
used  in  toning  the  latter — that  is,  where  gold 
is  used — unfortunately  too  often  omitted,  to 
the  entire  ruin  of  the  prints  in  point  of  per- 
manency. The  directions  for  printing  and 
developing,  which  accompany  each  package, 
are  so  simple  and  efficient  as  to  require  no 
additions  here.  They  cannot  be  improved 
upon,  and  the  formula  for  metol-quinol  devel- 
oper seems  to  be  perfect.  Pure  blacks  and 
whites,  with  soft  gray  half-tones,  may  be  de- 
pended upon  from  good  negatives  by  its  use. 
Some  subjects  are  decidedly  improved  by 
printing  in  browns,  sepias  or  reds.  All  of 
these  tones  may  be  obtained  by  using  the 
same  developer  greatly  diluted,  to  which  a 
few  grains  of  ammonia  carbonate  should  be 
added.  Long  printing  and  still  longer  devel- 
opment are  required  in  these  cases.  I  am  not 
prepared  to  give  more  extended  directions  for 
these  at  present,  not  having  done  enough 
work    by    this    printing    method    to    render 


PRINTING    METHODS  — LAN^E^IN?    SUDES  '     lOI 

certain  all  the  points  involvea^-bnti'cjuite' suM- 
cient  to  convince  me  of  its  ultimate  complete 
success,  as  well  as  desirability. 

Nothing  is  perfect — in  this  world,  at  least — 
and  Glossy  Velox  has  its  imperfections  in  com- 
mon with  all  things  mundane.  The  only  one 
of  any  consequence  that  I  have  noticed  is  its 
liability,  nay,  certainty,  of  developing  streaks 
or  spots  in  the  white  margins  around  the 
prints  as  usually  made  with  a  mask.  In  the 
thousands  of  prints  I  have  handled  in  all  the 
stages  from  printing  to  finishing,  I  have  not 
seen  one  entirely  free  from  these.  The  ma- 
kers say  that  they  are  caused  by  friction  in 
the  calendering  machines,  but  can  be  readily 
removed  by  rubbing  gently  with  a  tuft  of 
cotton  wool  moistened  with  alcohol.  What- 
ever the  cause,  most  decidedly  this  remedy 
will  not  answer  at  all.  It  is  utterly  worthless. 
They  further  say  the  marks  may  be  prevented 
by  the  addition  of  a  drop  of  a  lo  per  cent 
solution  of  potassium  cyanide  to  each  ounce  of 
developer.  Useless  again;  it  will  not  prevent 
the  marks.  They  may,  however,  be  instantly 
removed  by  the  expenditure  of  a  moment's 
work  on  each  print,  after  development,  fixing 
and  a  slight  washing.  Prepare  a  weak  solu- 
tion of  Farmer's  reducer,  as  follows: 


lO^       TH5    A    3    C.  OF.   PHOTO  -  MICROGRAPHY 

.  .  Hypo,  .     .\    ..   ,  . I  oz. 

Water 4  ozs. 

Ferricyanide  potass.  C.  P 10  grs. 

Take  each  print  separately  from  the  water, 
and,  holding  it  in  one  hand,  with  the  other  go 
over  it  very  carefully  with  a  moderately  large, 
round  camel's  hair  brush  filled  with  the  re- 
ducing solution,  taking  care  not  to  get  this 
over  the  margin  of  the  print  during  the  oper- 
ation. A  very  little  practice  will  render  one 
expert  in  this,  and  the  marks  will  disappear 
like  magic.  Running  water  should  be  al- 
lowed to  wash  over  the  face  of  print  fre- 
quently, in  order  to  prevent  any  action  of 
the  reducer  upon  the  print  itself,  should  some 
accidentally  get  upon  it.  Final  washing  and 
drying,  as  usual,  must  follow. 

Since  the  above  paragraph  was  written,  I 
have  had  an  opportunity  of  using  another 
brand  of  paper,  possessing  all  of  the  good 
features  of  Velox,  with  the  additional  one  of 
an  entire  absence  of  the  surface  markings, 
which  are  such  a  disagreeable  feature  of  the 
latter,  the  sole  drawback  to  its  use  indeed 
that  I  have  found.  This  is  the  S-C-P  or 
"Slow  Contact  Paper"  of  Wellington  &  Ward, 
England.  It  has  the  same  perfect  surface  as 
the   Velox,  the  same  sensitiveness  and  is  de- 


PRINTING    METHODS  — LANTERN    SLIDES        IO3 

veloped  with  the  same  developer — Metol- 
Quinol.  In  rather  an  extended  use  of  it 
during  the  past  month  or  two,  I  have  not 
seen  a  single  instance  of  the  markings  so 
common  with  Velox,  and  as  it  is  coated  on 
a  much  heavier  stock,  the  prints  are  even 
better  without  mounting  than  are  those  of 
the  latter  make.  I  am  not  sure  if  it  can  be 
obtained  in  this  country,  but  think  it  likely 
that  Wm.  C.  CuUen,  6i  William  street,  New 
York,  who  makes  a  specialty  of  foreign  pho- 
tographic articles,  may  be  able  to  supply  it. 
I  am  sure  it  is  worth  trying,  at  least. 

Photo-micrographs,  as  a  rule,  look  better 
and  are  more  pleasing  when  printed  under  a 
mask  with  circular  opening  of  suitable  size 
for  the  object,  leaving  a  white  margin  about 
the  picture,  which  then  is  of  the  same  shape  as 
the  field  seen  in  the  microscope  itself.  These 
masks  may  be  made  with  the  dark  orange- 
yellow  "post-office"  paper  to  be  had  every- 
where, and  which  is  perfectly  safe  for  the 
slow  emulsions  used  in  sensitizing  all  print- 
ing papers.  The  openings  are  readily  cut  by 
means  of  a  "form"  and  a  revolving  wheel 
cutter.  There  has  recently  been  introduced, 
at  a  trifling  cost,  a  set  of  forms  of  various 
shapes  and  sizes,  together  with  a  cutter,  which 


104      THE    A   B    C    OF    PHOTO  -  MICROGRAPHY 

may  be  had  from  all  photographic  supply 
houses.  This  is  a  veritable  boon  to  the 
printer  and  lantern-slide  maker. 

Photo-micrographic  prints  on  glossy  sur- 
faced paper  are  vastly  improved  by  "  squee- 
geeing "  on  a  ferrotype  plate,  but  the  process 
is  so  great  a  bugaboo  to  many  that  they  fail 
to  follow  it,  and  thus  lose  the  best  features  of 
such  a  print;  but  if  properly  done  in  all  its 
stages,  nothing  can  be  easier  or  more  abso- 
lutely certain  of  success  than  this  sometime 
dreaded  method  of  finishing  a  print.  In  the 
first  place,  the  ferrotype  plate  itself  is  one  of 
the  most  important  factors,  if  it  be  desired 
to  have  it  give  continued  and  uniform  good 
service.  In  selecting  it  get  the  besty  with  per- 
fect face  and  double  thick,  in  order  to  pre- 
vent wrinkling  (so  common  with  thin  plates), 
and  have  each  sheet  cut  in  half  crosswise, 
giving  two  plates  7x10  inches.  Each  of 
these  will  hold  at  one  time  four  prints  3^x4^ 
or  two  4x5,  the  most  common  sizes  used  in 
photo-micrography.  One  print  each  5  x  7  or 
6%  X  8%  may  be  placed  upon  them  if  a  larger 
camera  be  used.  We  now  face  two  problems, 
however,  each  of  much  greater  importance 
than  the  choice  of  the  plate  itself.  One  is  to 
bring   the   surfaces  of    print   and    plate    into 


PRINTING    METHODS — LANTERN    SLIDES        IO5 

perfect  contact  without  the  thinnest  stratum 
of  air  between  them ;  the  other  to  devise  some 
means  of  effectually  and  certainly  preventing 
the  print  from  sticking  to  the  plate  when 
dry — a  fatal  incident  in  the  life  of  the  former 
always,  and  not  infrequently  so  to  the  latter. 
All  gelatine  emulsions  coated  on  paper  are 
liable  at  times,  especially  in  hot  weather,  to 
softening  whilst  wet,  usually  in  spots,  rarely 
all  over  the  entire  surface.  Even  Velox  is  not 
entirely  free  from  it,  though  more  nearly  so 
than  any  other  paper  I  have  ever  used.  In 
this  condition  it  is  like  the  most  tenacious 
glue,  insoluble  in  water  cold  or  hot,  and  sticks 
with  such  pertinacity  to  the  ferrotype  plate  as 
to  become  inseparable  from  it  except  by  de- 
struction of  the  paper  and  practical  ruin  of 
the  plate  for  squeegeeing  purposes.  I  have 
now  a  plate  to  which  two  prints  stuck  in  this 
manner  several  years  ago,  and  thus  far  they 
have  resisted  every  attempt  at  removal.  I 
keep  it  as  a  terrible  example  and  for  experi- 
mental purposes.  Fortunately  I  long  ago  dis- 
covered a  preventive  remedy  for  this  defect, 
and  the  perfect  contact  of  plate  and  print  is 
very  easily  and  certainly  effected. 

When  the   prints   have    been    fully  washed 
and  freed  from  all  traces  of  hypo,  they  should 


I06      THE    A   B    C    OF    PHOTO  -  MICROGRAPHY 

be  transferred  to  a  tray  containing  a  solution 
of  water  and  formaldehyde  (in  the  propor- 
tions of  one  drachm  of  the  latter  to  four 
ounces  of  the  former),  in  which  they  are  to 
remain  until  needed.  A  tray  of  sufficient 
dimensions  to  contain  one  of  the  plates  (say 
8  X  10,  though  10  X  12  is  better)  is  then  to  be 
filled  with  water  and  placed  conveniently  near 
the  other.  Then,  holding  the  plate  under 
the  tap,  with  water  running  gently  over  its 
surface,  wash  the  latter  with  a  tuft  of  fine 
absorbent  cotton,  taking  great  care  not  to 
scratch  it,  and  transfer  the  plate  to  tray  (pol- 
ished side  upward),  making  sure  it  is  plenti- 
fully covered  by  the  water  and  that  no  air- 
bells  have  formed  on  its  surface.  It  should 
have  been  stated  that  it  will  be  well  to  place 
the  prints  in  the  formaldehyde  bath,  face 
upward,  turning  them  over  in  a  few  minutes, 
at  the  same  time  carefully  noting  whether 
any  air-bells  have  formed  upon  them;  if  so, 
they  must  be  removed  and  the  prints  turned 
over,  face  down.  All  being  now  ready,  and 
supposing  our  prints  to  be  4  x  5  inches  in  size, 
I  take  by  the  corners,  one  in  each  hand,  and, 
raising  them  from  the  bath  by  a  sliding  mo- 
tion, transfer  them  in  the  same  manner  to  the 
other  tray,  quite  certain  that  they  have  carried 


PRINTING    METHODS —  LANTERN    SLIDES       IO7 

no  air  with  them,  and  that  nothing  but  water 
intervenes  between  their  surfaces  and  that  of 
the  plate.  Observe  that,  having  pushed  each 
into  position,  all  beneath  the  water,  I  grasp 
the  plate  and  prints  by  thumb  and  fingers  of 
each  hand,  and  raise  out  of  the  water  again 
by  a  sliding  motion,  allowing  the  surplus 
moisture  to  run  off  at  the  bottom,  whilst  the 
prints  adhere  quite  closely  to  the  wet  plate. 
Now  carefully  wipe  the  prints  and  both  sides 
of  plate  with  a  soft  sponge,  taking  care  not 
to  move  the  former,  as  they  are  not  yet  very 
firmly  attached  to  the  plate,  more  or  less 
water  still  intervening  between  their  surfaces, 
but  after  passing  a  flat  rubber  squeegee  sev- 
eral times  over  them  they  may  be  handled 
almost  with  impunity.  The  final  act  is  to  lay 
the  plate  upon  a  table,  prints  upward,  and 
place  over  them  a  smooth,  absorbent  linen 
towel,  passing  the  squeegee  somewhat  vigor- 
ously over  its  surface  several  times,  until  all 
moisture  is  apparently  abstracted.  Then  re- 
move them  to  a  dry  place — if  possible  in  a 
gentle  current  of  air — to  dry  spontaneously, 
when  they  will  probably  peel  off  the  plate  of 
their  own  accord ;  at  farthest,  a  slight,  steady 
pull  by  one  corner  will  dislodge  them.  On 
no  account  must  this  be  attempted  until  they 


I08       THE    A    B    C    OF    PHOTO  -  MICROGRAPHY 

arc  "  bone  dry,"  and  It  must  always  be  done 
by  one  steady  pull ;  a  succession  of  them  will 
leave  a  series  of  disfiguring  creases  across  the 
print.  The  ferrotype  plates  should  be  care- 
fully laid  away  from  dust  in  a  drawer  or  box 
face  to  face,  with  a  sheet  of  tissue  paper 
between.  When  taken  out  for  use  they 
should  always  be  carefully  washed  with  a  tuft 
of  cotton  wool,  as  already  described.  It  will 
not  do  any  harm  to  wipe  them  occasionally 
with  a  soft  cloth  and  a  little  coal-oil,  followed 
by  a  perfectly  dry  cloth,  always  quite  soft,  to 
avoid  danger  of  scratching  the  polished 
surface. 

Blue  prints,  when  carefully  made  on  suit- 
able paper,  are  very  satisfactory  for  many 
classes  of  objects,  pleasing  the  artistic  eye 
and  rendering  delicate  details  with  astonish- 
ing fidelity.  The  ordinary  commercial  papers, 
however,  are  totally  unsuited  to  our  work; 
their  surfaces  are  not  smooth  enough,  nor  are 
the  whites  at  all  pure.  Every  photo-micro- 
grapher  who  elects  to  use  this  method  of 
printing  should  prepare  his  own  paper,  hence 
I  am  led  to  give  a  few  simple  directions  for 
so  doing.  The  best  paper  for  the  purpose 
with  which  I  am  acquainted  is  Rives'.  It  is 
pure  linen,  of  medium  weight,  heavily  sized 


PRINTING    METHODS  —  LANTERN    SLIDES        IO9 

and  perfectly  white.  It  may  be  procured  of 
any  photo-stock  dealer.  The  chemicals  are 
but  two  in  number,  both  very  cheap,  and 
should  be  chemically  pure.  They  are  potas- 
sium ferricyanide  (red  prussiate  of  potash)  and 
ammonia  citrate  of  iron.  To  make  the  sen- 
sitizing solution,  dissolve  just  before  using,  64 
grains  of  the  red  prussiate  in  i  ounce  af 
water,  and  lOO  grains  of  the  iron  citrate  in  a 
like  quantity,  keeping  them  separate  to  the 
last  moment,  when  they  arc  to  be  filtered 
together  through  a  wad  of  wet  cotton  wool 
placed  in  the  bottom  of  a  small  funnel.  The 
paper,  having  been  previously  pinned  by  its 
four  corners  to  a  smooth  board  or  table-top, 
is  now  to  be  gone  over  with  a  fine  sponge 
dipped  into  the  filtered  solution,  in  regular, 
broad  strokes,  first  from  left  to  right,  always 
in  one  direction,  until  its  surface  is  com- 
pletely coated;  then  at  right  angles  to  the 
first  coating,  ending  at  the  upper  right  hand 
end.  If  properly  done  the  surface  will  be 
smooth  and  even,  without  lines  or  marks  of 
any  kind.  A  little  practice  will  make  perfect, 
as  in  other  things.  The  sheet  must  then  be 
hung  up  in  a  warm  place  to  dry,  which  it  will 
do  very  quickly.  All  of  these  operations 
must  be  done  by  lamp-  or  very  subdued  day- 


1 10       THE    A    B   C    OF    PHOTO  -  MICROGRAPHY 

light,  and  the  paper,  after  sensitizing,  must 
not  be  exposed  to  the  latter  except  in  print- 
ing. It  is  much  less  sensitive  than  a  silver 
coating,  but  the  whites  will  lose  in  purity  by 
a  very  short  exposure  to  daylight.  Printing 
should  be  done  by  direct  sunlight  and  con- 
tinued until  the  details  are  well  shown  in  a 
dirty  bronze  color.  The  prints  should  then 
be  placed,  face  down,  in  a  tray  of  water  for 
a  few  moments,  then  washed  through  several 
changes  and  finally  dried  between  sheets  of 
smooth  blotting-board  under  gentle  pressure. 
A  picture  thus  made  is  absolutely  permanent, 
and,  with  its  brilliant  blue  tint  on  a  snow- 
white  ground,  "a  thing  of  beauty  and  a  joy 
forever." 

Finally,  as  to  printing  methods  on  paper, 
I  would  advise  the  use  of  a  deep  printing 
frame  with  glass  front  and  of  ample  size,  say 
6%x8%  (my  own  favorite) — not  too  large, 
easy  to  handle,  **  just  right."  A  spoiled  nega- 
tive from  which  the  film  has  been  removed 
will  answer  for  the  front,  but  a  sheet  of  thin 
plate  glass  is  much  better,  as  it  is  perfectly 
flat.  The  breaking  of  a  negative  from  un- 
equal pressure  in  such  a  frame  is  well-nigh 
impossible;  all  sizes,  from  quarter  to  full 
plate,  may  be  printed  in  it,  and  in  making 


PRINTING    METHODS  — LANTERN    SLIDES       HI 

lantern-slides  by  contact  printing  any  portion 
of  the  negative  can  be  utilized,  which  is  not 
the  case  with  frames  of  small  sizes.  A  single 
frame  can  thus  be  made  to  do  the  work  of 
a  number — a  manifest  advantage. 

It  seems  almost  superfluous  to  say  aught 
as  to  the  making  of  lantern  slides  at  this  late 
day,  when  so  many  thousands  of  amateurs 
have  become  more  or  less  proficient  in  the 
art  formerly  in  the  hands  of  professionals 
alone;  but  the  excellent  dry  plates  of  thin 
glass,  so  readily  obtainable  everywhere,  with 
equally  thin  covers,  ready-cut  masks  and 
gummed  binding  strips,  have  made  the  pro- 
duction of  a  lantern  slide  so  easy  that  every 
one  undertakes  it  at  times,  and  with  very 
indiff^erent  success  in  the  majority  of  cases, 
mostly  preventable.  I  cannot  pretend  to  enu- 
merate the  causes  of  these  failures  or  their 
cure.  Every  one  is  familiar  with  the  wretched 
caricatures  too  frequently  shown  upon  the 
screen.  There  is  no  need  for  their  being, 
especially  in  photo -micrographs.  Secure  a 
good  negative  first;  after  that  proper  atten- 
tion to  a  few  simple  details  will  insure  the 
making  of  a  good  lantern  slide  from  it. 
Nothing  can  exceed  in  beauty  and  interest 
a    thoroughly    good    lantern    picture    shown 


112       THE    A   B    C    OF    PHOTO  -  MICROGRAPHY 

upon  the  screen  by  an  equally  good  light. 
It  should  stand  without  loss  the  searching 
rays  of  the  electric  arc,  and  may  truly  be 
termed  ^W  if  it  does  so. 

Excellent  plates  for  this  purpose  are  now 
furnished  by  all  the  leading  makers  of  nega- 
tive plates.  I  have  used  them  all  and  can 
testify  to  their  uniformly  good  qualities. 
They  vary  considerably  in  sensitiveness  and 
in  the  tones  produced  by  given  developers. 
I  have  found  it  most  satisfactory  on  the  whole 
to  use  the  particular  one  recommended  by 
the  makers,  who  seem,  one  and  all,  to  have 
worked  out  the  best  methods  in  each  case. 
I  have  already  elsewhere  spoken  of  the  entire 
satisfaction  with  which  I  have  used  exclusively 
for  over  a  year  past  the  Forbes  negative 
plates,  to  which  must  be  added  those  for 
lantern-slides,  which  I  have  also  employed 
during  the  same  period  of  time  with  such 
uniformly  good  results  as  to  leave  no  desire 
to  change.  They  are  quick,  give  brilliant 
pictures,  have  no  tendency  to  fog  or  frill, 
allow  great  latitude  of  exposure,  are  very 
easy  of  manipulation  and  cheap.  What  more 
could  one  desire? 

Two  methods  of  making  lantern-slides  are 
open  to  the   photo-micrographic   in  common 


PRINTING    METHODS  —  LANTERN    SLIDES       HJ 

with  all  Other  classes  of  negatives — by  contact 
printing  or  by  reduction  with  a  lens.  For 
the  latter  method  a  camera  like  the  E.  R.  &  C. 
(F^g-  3)  is  most  convenient,  though  work 
may  be  done  with  the  improvised  apparatus 
already  described  for  making  negatives.  This 
is  by  far  the  best  way  to  secure  the  most  sat- 
isfactory lantern-slides ;  and  when  the  negative 
must  be  reproduced  in  whole  but  is  of  too 
large  size  for  their  limits,  is  the  only  method 
by  which  it  can  be  accomplished.  It  is  not 
necessary  to  repeat  the  manipulations  already 
detailed  for  negative-making,  these  being  pre- 
cisely the  same,  excepting  that  the  image  is 
enlarged  in  the  one  case  and  reduced  in  size 
in  the  other. 

Contact  prints  are  made  in  the  same  man- 
ner as  those  upon  paper,  but  masking  out  of 
portions  of  the  negative  may  be  omitted. 
If  the  latter  has  been  made  with  a  view  to 
this  method  of  printing  it  on  a  lantern-slide, 
there  is  nothing  further  to  do  than  to  put 
the  film  surfaces  of  both  plates  together  and 
expose  in  a  printing-frame  to  lamp-  or  gas- 
light. If  only  a  certain  portion  of  a  larger 
negative  be  needed,  it  should  be  carefully 
placed  in  contact  with  the  center  of  lantern- 
plate    before    exposure.     Do    not    make    this 


114      THE    A   B    C    OF    PHOTO  -  MICROGRAPHY 

latter  too  long.  A  short,  but,  of  course, 
sufficient  exposure,  with  comparatively  long 
development,  will  give  clearer  high  lights  and 
more  transparency  in  the  shadows  than  the 
reverse;  but  be  careful  to  avoid  under-ex- 
posure, as  no  amount  of  forcing  or  other 
manipulations  will  ever  give  satisfactory  re- 
sults if  the  light  has  not  acted  its  part  upon 
the  sensitive  emulsion.  Experience  and  prac- 
tice alone  will  give  proficiency  in  this  some- 
what difficult  and  always  delicate  work.  You 
must  be  prepared  for  and  expect  some  fail- 
ures, since  you  are  certain  to  meet  with  them ; 
but  be  not  discouraged;  success  is  sure  to 
attend  upon  patient,  persistent  effort.  The 
spoiled  plates  need  not  be  wholly  wasted. 
After  keeping  them  long  enough  as  **  fright- 
ful examples  and  warnings,"  the  films  may  be 
cleaned  oflF  by  hot  water  and  the  plates  be 
used  as  cover-glasses  for  other  slides. 

All  lantern  slides  should  be  varnished,  but 
not  before  making  sure  they  are  worth  pre- 
serving and' require  no  further  doctoring,  as 
they  may  do  in  the  way  of  local  intensifica- 
tion or  reduction,  toning,  etc.  I  do  not  deem 
it  necessary  to  give  directions  here,  since  they 
are  so  fully  detailed  in  the  books  accessible 
to    all    at    this    time.     A  thin,  clear   varnish, 


PRINTING    METHODS  —  LANTERN    SLIDES        II5 

drying  hard  quickly  without  heat,  should  be 
used.  If  coloring  of  the  picture  is  decided 
upon  it  must,  of  course,  be  done  before  var- 
nishing. Many  subjects  are  greatly  improved 
by  judicious  application  of  transparent  colors, 
but  great  care  must  be  exercised  in  the  opera- 
tion. In  The  Photo-Miniature,  Vol.  I,  No.  9, 
**  Lantern  Slides,"  may  be  found  very  clear 
and  explicit  details  of  all  necessary  operations. 

The  finishing  of  a  lantern  slide  is  a  very 
important  factor  in  the  beauty  of  its  appear- 
ance. Slovenly-cut  masks,  dirty  backgrounds, 
pictures  upside  down  and  other  defects  —  all 
preventable — detract  largely  from  its  other 
good  features.  A  uniformity  of  mounting, 
in  so  far  as  possible,  is  greatly  to  be  desired. 
As  a  rule  each  maker  of  slides  seems  to  have 
either  his  own  pet  plans  or  no  plans  at  all, 
for  frequently  no  two  of  his  mounts  are  alike, 
with  results  most  embarrassing  to  the  unfor- 
tunate who  manipulates  the  lantern,  to  say  the 
least.  At  the  risk  of  appearing,  perhaps, 
somewhat  egotistical,  I  venture  to  give  my 
own  method  of  finishing,  which  seems  simple 
and  practical,  and  which  I  have  followed  for 
many  years  in  mounting  slides  of  photo- 
micrographs : 

After  varnishing  and  drying,  the  mask,  hav- 


Il6       THE    A    B    C    OF    PHOTO  -  MICROGRAPHY 

ing  circular  opening  if  possible,  from  2%  to 
2%  inches  in  diameter,  is  laid  upon  the  slide 
and  covered  with  the  previously  cleaned  thin 
glass  of  same  size.  Should  there  be  more 
than  one  to  finish,  all  are  treated  in  the 
same  manner  before  proceeding  farther.  A 
gummed  binding-strip  —  to  be  had  of  any 
dealer — is  now  to  be  taken  by  one  end  be- 
tween the  thumb  and  forefinger  and  drawn 
through  a  tray  of  water,  gummed  side  upper- 
most. When  lifted  from  the  tray  the  excess 
of  water  should  be  removed  by  drawing  it 
between  the  thumb  and  finger  of  the  other 
hand  with  a  gentle  pressure,  after  which  the 
back  may  be  dried  by  drawing  it  over  a  soft 
towel.  It  is  then  to  be  laid  upon  any  dry, 
hard  surface;  the  slide  and  cover-glass,  held 
between  the  thumb  and  finger,  are  pressed  by 
one  edge  along  its  center,  to  which  it  will 
adhere,  and  may  be  raised  from  the  table. 
Now  bend  it  carefully  around  the  corner  and 
repeat  until  all  four  sides  are  attached  to  the 
center  of  the  strip,  with  the  ends  overlapping 
a  little  at  one  end  of  the  slide.  Then  care- 
fully press  the  paper  along  each  side  firmly  to 
the  glass,  turning  the  corners  neatly  and  rub- 
bing all  down  smoothly  with  finger  and 
thumb.     This  may  not  be   a  success   at  the 


PRINTING   METHODS  —  LANTERN    SLIDES        II7 

first  trial,  but,  as  in  all  of  our  other  opera- 
tions, a  little  patient  work  will  make  perfect. 
It  would  be  well  to  practice  with  a  dummy 
slide  until  the  ** knack"  is  acquired.  Now 
come  the  finishing  touches.  Lay  the  slide 
flat  upon  the  table,  cover  side  up,  and  with 
the  top  of  the  picture  as  you  wish  it  to  appear 
upon  the  screen  also  at  top  of  slide  as  it  lies 
before  you.  In  other  words,  it  should  be 
in  exactly  the  position  you  desire  it  to 
occupy  on  the  screen.  Then  gum  a  circle  or 
square  of  white  paper  to  the  lower  left-hand 
corner^  as  shown  in  Fig.  27.  Now  turn  the 
slide  over  from  top  to  bottom  {not  from  right 
to  left),  and  gum  the  label  on  left-hand  side, 
as  shown  in  Fig.  .28,  which  will  bring  it  over 
the  spot  on  face  of  slide.  If  then  the  opera- 
tor, when  putting  a  slide  into  the  carrier,  does 
so  with  this  spot  label  always  on  top  and 
facing  the  screen,  the  picture  must  be  pro- 
jected right  side  up  and  just  as  you  have 
designed  it  to  be  shown. 

The  picture  on  a  lantern-slide  must  fill 
either  the  entire  space  of  cut-out  in  the  mask 
or  only  a  portion  thereof  with  a  margin  of 
clear  glass  or  slightly  tinted,  as  the  negative 
may  be  more  or  less  dense.  The  appearance 
of  such  a  slide  as  the  latter,  is  greatly  marred 


ii8 


THE    A    B    C    OF    PHOTO  -  MICROGRAPHY 


by  a  dirty  or  imperfect  background  highly 
magnified  on  the  screen,  and  the  utmost  care 
should  be  taken  to  avoid  this,  not  only  in 
making  both  negative  and  positive,  but  also 
in  the  preparation  of  the  object  to  be  photo- 
graphed. The  mounting  should  be  abso- 
lutely clean  and  free  from  specks  of  any 
foreign  substance.  No  subsequent  careful- 
ness in  the  photographic  manipulations  can 
entirely  compensate  for  defects  in  a  faulty 
microscopic  preparation. 

Two  illustrations,  representing  the  front 
and  back  of  a  lantern  slide  prepared  in  ac- 
cordance with  the  foregoing  directions,  are 
given.  They  are  of  the  standard  American 
size  —  3%X4  inches.  Fig.  27  is  a  transverse 
section  of  a  compound  ovary,  magnified  20 
diameters,  and  occupies  the  center  of  the  cut- 
out, with  clear  glass  about  it.  Fig.  28,  the 
compound  eyes  of  a  water-beetle  {Dytiscus 
Marginalis)^  +75^  fiUs  the  entire  circle.  Each 
of!  these  facets  or  eyes  being  a  convex  lens, 
shows  an  image  of  the  radiant  used  in  mak- 
ing the  negative.  Both  slides  were  printed  by 
contact,  as  with  a  paper  print. 


CHAPTER    VII 


General  Notes 


i 


In  my  note-book  are  a  number  of  sugges- 
tions which  may,  perchance,  be  of  interest  to 
some  of  my  readers,  but  could  not  well  be 
incorporated  with  any  of  the  preceding  chap- 
ters. Taken  at  random  from  its  pages,  I  pre- 
sent them  in  collected  form,  with  the  hope 
that  they  may  be  useful  to  a  few,  at  least, 
which  is  my  excuse  for  adding  them  at  all. 

Note -Book.  I  would  urge  upon  all  who 
intend  giving  serious  attention  to  photo- 
micrography the  great  importance  of  keeping 
liberal  notes  of  each  negative  they  make,  in 
some  clear  and  simple  form.-  These  should 
include  date  of  exposure,  objective,  ocular, 
condenser,  plate,  screen,  radiant,  length  of 
exposure,  developer,  amplification,  etc.  It 
would  add  still  further  to  the  value  of  such 
notes  if  the  stain  used  in  making  preparations 
were  given  also.  The  note-book  should  be  of 
ample  size  and  may  be  ruled  to  suit  the  ideas 
of  each  worker,  or  left  blank  if  he  prefers. 
A  form  shown  on  the  next  page  is  good. 

(119) 


120       THE    A    B    C    OF    PHOTO  -  MICROGRAPHY 


M 

1 

^ 

g. 

H 

o 

1 

1 

S" 

"i  b 

is 

e 

i2 

6  2 

i2 

6  2 

<3^ 

Jd  tJ 

J<  TS 

Ji<  13 

Ji<TJ 

S£ 

5 

"K 

5£ 

wa 

«K 

1 

n 

H 

c 

_Q 

11^ 

SI 

T3     O 

1§«* 

J3-£«5 

sL 

s; 

|o 

«ozX 

15 

|o 

|o 

"^ 

L~ss 

|5 

a 

Is 

i-n-SS 

•|f  gs 

2 

|.i-o!i 

^  « 

Ji 

s  « 

^.5uS^ 

CO 

i.a.-s« 

S" 

O 

^" 

hPU   «   M«»« 

hS  «  SlM 

1 

Is 

'5 

H 

d 

.2 

,    ■* 

w 

^ 

^'Z  c 

s 

1  «    . 

£ 

xi 

lit 

a 

a,  a"* 

O 

O 

o  ^- 

IH^ 

O 

<   G  -• 

z 

M 

Z 

£| 

V. 

S  .ii  c  1 

6  o 

^     1     o 

u 

S  2.2 

«  2  *^ 

,=  « 

•f^  «  "V  ^ 

jO    o  • — 

c 
o 

•«•«  « 

«•«  « 

"- 

o 

Is 

<«  E 

Z 

N^  E 

N^E 

*» 

«d 

^ 

£ 

O 

H  E 

K 

cO 

M 

:^ 

£^ 

2 

£"E 

>*l 

^e 

u 

pa 

CO 

'5 

NJ 

^^ 

et  u 

, 

c 

1 

jj 

'n  o 

.2 

x> 

1^ 

V 

tj 

a 

"rt 

9 

•*=    3 

-SJ  u 

(O 

w 

O.^ 

•o 

•3  a 

1 

ll 

a 

•S'S 

T3 

.s 

"SI 

«o 

O    1 

O 

1 

09 

O    3 

^    I 

«•  1 

0) 

«« 

o    . 

r.2 

1 

E.S 

85 

C 

*J3 

ll 

n 

o 

CO 

w 

u 

n 

o 

^ 

i/> 

t^ 

w^ 

v^ 

H 

1     ^ 

«l 

II 

>> 
«« 

c 
a 

c 

9 

s 

S 

4 

I 

t 

8 

1 

I 

1 

M 

GENERAL     NOTES  121 

The  purposes  such  a  list  will  serve  are  nu- 
merous and  varied.  One  of  the  most  import- 
ant of  these  is  the  information  it  imparts  as 
to  plate,  illumination,  exposure,  etc.,  which 
have  produced  satisfactory  negatives  as  guid- 
ance in  future  cases  of  similar  character,  until 
experience  shall  have  given  the  worker  intui- 
tive knowledge,  as  it  were,  of  the  best  meth- 
ods of  handling  every  class  of  subject. 

Numbering  Negatives.  Systematic  work  is 
urged  throughout,  and  from  the  very  begin- 
ning. One  most  important  point  is  the  num- 
bering of  every  negative  in  a  permanent  and 
legible  manner.  This  should  be  done  before 
exposure,  to  guard  against  forgetfulness  and 
possible  confusion  afterward.  There  may  be 
various  plans  adopted.  My  own,  which  has 
stood  the  test  of  practical  use  during  many 
long  years,  is  simple  in  the  extreme.  The 
only  tools  required  are  a  good  lead-pencil  of 
medium  hardness  only  (indeed  it  is  better  to 
incline  somewhat  to  the  soft  side),  with  a 
fairly  blunt  point,  and  a  sheet  of  cardboard 
sufficiently  large  to  cover  the  plate.  When 
about  to  place  the  latter  in  holder,  lay  it,  face 
upward,  in  front  of  the  ruby  lantern,  covered 
by  the  card,  excepting  a  narrow  strip  of  its 
lower   edge,   to    protect    it    from    the    light. 


122       THE    A    B    C    OF    PHOTO  -  MICROGRAPHY 

Then  write  the  number  in  strong,  well-formed 
figures  in  the  left-hand  corner,  using  consider- 
able pressure,  but  not  enough  to  break  the 
pencil  point  or  scratch  the  film.  After  devel- 
opment these  figures  will  remain  perfectly 
legible  and  permanent.  The  corresponding 
number,  with  particulars,  entered  in  the  note- 
book at  the  same  time,  completes  the  record. 
Storing  Negatives.  As  the  number  of  our 
negatives  increases,  the  necessity  of  storing 
them  in  some  systematic  manner  which  will 
keep  them  in  safety  and  at  the  same  time 
facilitate  the  prompt  finding  of  any  one  as 
needed,  becomes  more  and  more  apparent,  if 
we  have  not  started  to  do  so  at  the  outset  of 
our  work.  It  is,  therefore,  wise  to  begin  this 
important  item  with  the  very  first  negative 
made.  Two  methods  are  suggested,  both  of 
which  have  been  found  good  and  practical. 
In  the  first,  the  negatives  are  to  be  placed  in 
empty  plate-boxes  of  same  size,  with  a  sheet 
of  paper  between  each  pair,  and  the  numbers 
written  on  the  end  of  box,  these  in  turn  being 
piled  on  shelves  in  a  dry  room,  with  the  num- 
bered ends  in  front.  They  are  thus  kept  free 
from  dust  or  other  injury,  and  any  one  can  be 
readily  found  after  reference  to  the  note-book 
record  of  its  number.     A  serious  objection  to 


GENERAL    NOTES  I 23 

this  plan  is  the  facility  it  affords  for  scratch- 
ing the  gelatine  film.  Very  frequently  the 
plate  wanted  proves  to  be  the  bottom  one 
in  the  box,  necessitating  the  removal  and 
replacing  of  all  the  others  in  obtaining  it.  A 
careless  movement  might  seriously  mar  the 
perfection  of  a  valuable  negative  in  a  mo- 
ment. This  danger,  however,  can  be  greatly 
lessened  by  coating  the  film  with  a  hard 
varnish. 

The  second  method  which  I  would  suggest 
as  being  altogether  preferable,  is  to  place 
each  negative  in  an  envelope  of  stout  manila 
paper, —  sold  by  all  stock  dealers  under  the 
name  of  negative  preservers, — with  its  number 
plainly  written  on  the  face.  These  are  stood 
on  end  upon  a  shelf  in  numerical  succession, 
where  they  are  fully  protected  from  injury, 
and  are  instantly  accessible.  As  their  number 
increases  it  will  become  more  and  more  diffi- 
cult to  pick  out  a  desired  one  from  the  note- 
book. At  this  point  recourse  to  card  cata- 
loguing, as  with  a  library,  will  effectually 
remove  all  trouble  and  greatly  facilitate  the 
finding  of  any  desired  negative. 

Varnishing  Negatives.  In  a  dry  climate  like 
ours  the  varnishing  of  gelatine  negatives  is 
not   at   all  necessary,  unless   very  large   num- 


124      THE    A    B    C    OF    PHOTO  -  MICROGRAPHY 

of  prints  are  to  be  made  from  any  one,  in 
which  case  it  is  recommended  to  do  so.  And 
if  we  have  unfortunately  to  employ  the  services 
of  a  printer,  it  is  well  to  varnish  the  negatives 
first,  as  a  safeguard  against  carelessness.  A 
hard  varnish,  drying  without  heat,  should  be 
used  and  must  not  be  applied  unless  the  film 
is  entirely  free  from  moisture,  in  fact  **  bone- 
dry."  Neither  should  it  be  done  before  a 
print  is  made  and  the  negative  found  to  be 
satisfactory  in  all  particulars,  since  no  altera- 
tions, such  as  reducing  or  intensifying,  can  be 
made  without  its  removal.  This  may  be  done 
by  immersion  in  alcohol,  but  it  is  much  better 
to  be  sure  that  the  negative  is  all  right  first. 

Intensification.  A  perfect  negative  of  course 
is  one  which  needs  no  after-treatment  when 
the  development  is  finished;  specimen,  lens, 
illumination,  exposure,  developer,  having  alike 
done  their  parts  in  producing  a  harmonious 
whole.  It  is  what  we  strive  for  throughout, 
and  thanks  to  the  present  perfection  of  opti- 
cal apparatus  and  dry  plates,  is  very  generally 
reached  by  all  who  have  had  some  practical 
experience  and  earnestly  work  for  it  always. 
But  there  are  frequent  unforeseen  contin- 
gencies to  be  met,  which  disappoint  our  ex- 
pectations and  require  the  making  of  another 


GENERAL     NOTES 


125 


negative,  or  a  **doctormg"  of  the  defective 
one.  The  beginner  must  not  yield  to  dis- 
couragement should  his  most  careful  work 
turn  out  a  failure.  Such  contretemps  vi^ill 
happen  to  the  most  experienced  workman. 
We  do  not  usually  show  our  failures,  and  only 
the  operator  himself  ever  knows  how  long  a 
list  of  them  have  been  charged  off  to  profit 
and  loss.  It  is  well,  therefore,  to  be  prepared 
for  troubles  and  how  to  meet  them.  As  it  is 
impossible  in  this  connection  to  enumerate  all 
that  may  arise,  I  shall  confine  myself  to  two 
or  three  of  the  most  common  ones  and  their 
remedies. 

Assuming  that  both  optical  and  photo- 
graphic appliances,  including  plates  of  course, 
are  of  good  qualities,  the  majority  of  failures 
are  due  to  under-  or  over-timing  of  the  expos- 
ure, and  to  under-  or  over-development  of  the 
plate.  The  first  of  these  I  shall  dismiss  at 
once  in  a  single  sentence, —  make  another  ex- 
posure,— for  a  really  under-timed  negative  can 
never  be  successfully  after-treated.  An  over- 
exposed plate  probably  gives  more  frequent 
trouble  to  the  novice  than  any  other  thing, 
but  fortunately  he  can  usually  remedy  it. 
The  development  commences  so  quickly  and 
proceeds  with   such   rapid   strides  that   he   is 


126       THE    A    B    C    OF    PHOTO  -  MICROGRAPHY 

alarmed,  fearing  the  entire  plate  will  be 
equally  blackened  throughout  and  com- 
pletely ruined.  He  thereupon  removes  it 
from  the  developing  bath,  washes  hurriedly 
and  places  in  the  hypo  solution  quickly  as 
possible,  in  order  to  prevent  this  dreaded 
result,  only  to  find  after  fixation,  that  the 
negative  is  full  of  detail  but  so  utterly  lack- 
ing in  density  or  contrasts  as  to  be  quite 
unprintable.  The  plate,  however,  is  not  neces- 
sarily wasted,  nor  need  another  exposure  be 
made  in  most  cases,  as  required  in  under- 
timing.  Unless  the  negative  is  hopelessly 
over-exposed,  very  thin  and  flat,  intensification 
will  usually  put  it  into  shape  for  producing 
good  prints.  There  are  many  ways  of  doing 
this,  to  be  found  in  all  books  on  photography, 
and  I  shall  give  but  two  here  which  I  know 
to  be  good  and  reliable.  The  first  has  had 
nearly  twenty  years  of  continual  use  in  my 
hands  without  a  failure,  hence  I  recommend 
it  without  any  hesitation  or  reservation.  I  am 
indebted  for  it  to  an  article  in  an  old  number 
of  The  British  Journal  of  Photography's 
Almanac — under  the  heading  of  **  Cyanide  of 
Silver  Intensifier."  Every  one,  of  course,  is 
familiar  with  the  old  method  of  intensification 
by  first   bleaching  with   a  mercurial   solution 


GENERAL     NOTES  I 27 

and  subsequent  blacking  by  treatment  with 
ammonia,  sodium  sulphite,  or  other  agents. 
I  had  long  used  them  all  with  very  unsatis- 
factory results  as  to  permanence,  when  I  saw 
this  formula  in  the  aforementioned  journal 
and  tried  it,  with  such  success  that  I  have 
had  no  wish  to  make  any  change.  It  always 
works  satisfactorily  and  I  have  never  had  a 
negative  change  in  any  manner  after  its 
application.  It  consists  of  two  solutions, 
which  may  be  used  repeatedly  without  appa- 
rent exhaustion.  I  renew  them  occasionally, 
say  once  or  twice  in  a  year,  more  from  habit 
than  necessity,  as  the  old  solutions  appear  to 
act  quite  as  well  as  fresh  ones,  though  rather 
more  slowly.  The  formula  is  as  follows,  to 
be  put  in  two  bottles: 

A 

Mercury   bichloride 96  grs. 

Potass,  bromide .  96  grs. 

Water,  distilled 12  ozs. 

B 

Potass,  cyanide,  chem.  pure  .     .     .     .  90  grs. 

Silver    nitrate 96  grs. 

Water,  distilled 12  ozs. 

Shake  well  and  allow  to  settle ;  keep  the  pre- 
cipitate—  cyanide  of  silver — always  at  bottom 


128       THE    A    B    C    OF    PHOTO  -  MICROGRAPPTSf 

of  the  bottle.  It  will  be  good  for  use  so  long 
as  any  precipitate  remains. 

The  negative  to  be  intensified  (which  must 
be  absolutely  free  from  hypo),  after  being 
well  wetted,  is  immersed  in  A  until  bleached 
to  the  desired  extent.  If  great  density  is 
required  it  should  be  whitened  entirely 
through  the  back,  but  merely  grayed  over 
the  surface  if  but  slight  intensification  is 
desired.  It  must  then  be  very  freely  washed 
for  fifteen  minutes  in  running  water,  or  sev- 
eral changes  if  the  former  is  not  convenient. 
And  herein  lies  one  of  the  cardinal  factors  in 
the  permanence  of  the  negative  —  thorough 
washing  at  every  stage  of  its  making.  In  the 
quaint  diction  of  the  formula  as  found  in 
the  old  Journal 

**  Three  rules,  which  must  be  carefully  obeyed,  are 
necessary  to  insure  permanence  in  the  intensified  nega- 
tive. And  what  is  the  first  rule?  Wash  thoroughly. 
And  what  is  the  second  rule  ?  Wash  thoroughly.  And 
what  again  is  the  third?     Wash  thoroughly." 

The  negative  is  now  to  be  immersed  in  Solu- 
tion B  until  completely  blackened  through  on 
the  back;  then  again** washed  thoroughly"  and 
placed  in  a  rack  to  dry  spontaneously.  Thus 
treated  it  will  never  change  in  any  manner 
more  than  one  which  has  not  been  intensified. 


GENERAL     NOTES  I 29 

Somewhat  recently  we  have  from  Germany 
an  intensifying  medium,  which  is  sold  in  a 
concentrated  form  under  the  name  of  **Agfa." 
A  dilute  solution  having  been  made  as  per 
accompanying  directions,  the  plate  to  be 
intensified  is  simply  soaked  therein  until  the 
required  degree  of  density  is  reached,  which 
may  be  noted  as  that  process  advances,  after 
which  washing  and  drying  succeed  each  other 
as  before.  The  resulting  negative  is  of  an 
agreeable  brownish  color  and  excellent  print- 
ing qualities,  whilst  its  permanence  is  said 
to  be  unquestionable.  I  have  used  Agfa  with 
great  satisfaction,  but  have  seen  nothing  in 
it  to  tempt  abandonment  of  the  silver  cyanide 
intensifier.  Of  course  both  methods  are 
equally  applicable  to  the  rather  frequent 
cases  of  under-development  of  properly  ex- 
posed plates,  or  those  which  have  been  oven 
timed  as  described. 

Reducing  Density.  It  not  infrequently  hap^ 
pens,  from  some  cause, —  generally  over-devel^ 
opment  of  a  fully  exposed  plate, — that  the 
negative  is  too  dense  for  printing.  If  it  be 
otherwise  right,  reduction  of  the  over-density 
may  enable  us  to  utilize  it  with  good  results. 
This  is  generally  effected  by  immersion  in 
Farmer's    Solution  —  formula    for    preparing 


130      THE    A   B    C    OF    PHOTO  -  MICROGRAPHY 

which  is  given  in  all  books  on  photography, — 
until  the  desired  reduction  is  reached,  when 
it  is  to  be  washed  and  dried  spontaneously. 
My  own  practice  is  to  make  this  reducer  by 
"rule  of  thumb,"  as  follows:  About  half  an 
ounce  of  potass  ferricyanide  (red  prussiate  of 
potash)  is  dissolved  in  four  ounces  of  water, 
and  put  in  a  well-stoppered  bottle,  where  it 
will  keep  very  well  in  a  dark  place  or  if  the 
bottle  is  covered  with  opaque  paper,  the 
solution  spoiling  if  exposed  to  light  in  a 
short  time :  this  is  kept  for  stock.  To  make 
the  reducer,  I  dissolve  i  ounce  of  sodium 
hyposulphite  in  4  ounces  of  water,  and  add 
a  small  quantity  of  the  ferricyanide  solution, 
stirring  the  whole  to  mingle  the  ingredients 
evenly.  Should  its  action  be  abnormally  tardy, 
more  of  the  ferricyanide  may  be  added,  but 
a  slow,  steady  reduction  by  a  somewhat  weak 
solution  gives  more  satisfactory  results  than 
rapid  work  with  a  strong  one.  This  bath 
will  not  keep  and  should  be  thrown  away 
after  using. 

Persulphate  of  ammonium  is  also  a  most 
excellent  reducing  agent,  and  as  it  seems  to 
attack  the  denser  portions  of  the  negative 
first  is  especially  valuable  in  many  cases.  A 
2    per   cent    solution    is    about    the    proper 


GENERAL     NOTES  I3I 

Strength  for  general  use.  Reduction  com- 
mences at  once,  and  proceeds  at  times  some- 
what rapidly,  rendering  a  careful  watching 
quite  necessary.  When  the  desired  amount 
of  reduction  is  reached,  the  negative  must 
be  removed  at  once  to  a  bath  of  sodium  sul- 
phite and  water  —  no  particular  strength  being 
required, — to  stop  reduction,  which  will  con- 
tinue energetically  in  the  presence  of  water 
alone;  after  which  it  is  to  be  thoroughly 
washed  and  dried  as  usual. 

"Agfa "-reducer  is  a  recently  introduced 
material,  said  to  possess  many  very  desirable 
qualities  for  that  purpose.  I  have  not  used 
it,  but  from  the  many  good  words  spoken 
of  it,  think  it  well  to  call  the  attention  of  my 
readers  to  it.  The  article,  as  sold,  is  highly 
concentrated,  merely  requiring  to  be  diluted 
with  ten  parts  of  water  for  use.  Complete 
reduction  takes  place  in  a  few  minutes,  the 
length  of  time  required  being  governed  by 
the  density  of  negative  to  be  reduced. 

Mechanical  Local  Reduction.  Occasionally 
an  object  which  does  not  present  very  marked 
contrasts  visually  as  seen  in  the  microscope, 
becomes  an  altogether  different  subject  under 
the  photographic  eye;  portions  of  the  nega- 
tive  being   so  dense  that   no   light  can  pass 


132       THE    A    B    C    OF    PHOTO  -  MICROGRAPHY 

through  them,  whilst  other  parts  may  be  full 
of  detail  though  quite  lacking  in  printing 
density.  It  is  manifestly  impossible  in  such 
cases  to  effect  sufficient  reduction  in  the 
overly  dense  portions  by  chemical  methods, 
without  obliterating  details  in  the  shadows, 
making  the  last  stage  of  the  unfortunate 
negative  worse  than  the  first.  A  method  of 
mechanical  reduction,  which  may  not  be  so 
generally  known  as  it  deserves,  has  an- 
swered so  well  in  my  own  work  that  I  feel 
inclined  to  include  it  with  these  notes  for  the 
benefit  of  those  who  may  not  be  familiar  with 
it.  The  requisite  materials  are  few  and  inex- 
pensive: a  little  alcohol  or  methylated  spirits, 
a  finger  from  an  old  kid  glove,  and  patience. 
The  kid  is  to  be  simply  wetted  with  the 
spirits  (its  inner  surface  is  the  better), 
stretched  over  the  forefinger  and  the  dense 
spot  gently  rubbed  with  a  rotary  motion, 
until  the  desired  amount  of  reduction  is  ob- 
tained. The  process  is  a  slow  one,  demand- 
ing the  exercise  of  care  and  patience.  In 
stubborn  places,  the  wetting  with  alcohol  may 
have  to  be  repeated  several  times.  No  por- 
tion of  the  negative  will  be  affected  but  the 
spot  that  is  rubbed.  Should  this  be  too  small 
for   the    finger   to    manipulate    properly,   the 


GENERAL     NOTES  133 

piece  of  kid  may  be  stretched  over  some 
suitable  article,  the  blunt  end  of  a  pencil  for 
instance,  or  better,  the  small  rubber  eraser 
attached  to  pencils,  which  may  be  procured 
for  a  few  cents.  If  carefully  done,  this 
method  of  mechanical  reduction  will  be  found 
exceedingly  useful  and  satisfactory  in  cases 
where  no  other  could  be  used. 

Potassium  Bromide.  Although  the  brom- 
ides of  potassium  or  ammonium  are  so  gen- 
erally recommended  and  used  as  restrainers, 
my  own  experience  has  not  been  favorable  to 
them.  Slow  development,  with  rather  weak, 
or  even  dilute  solutions,  has  always  given 
better  results  in  every  way — details,  density, 
evenness.  With  Eiko-Hydro  developer,  the 
addition  of  about  one-fourth  volume  of  an 
old  and  used  solution  to  the  fresh  mixture 
is  very  satisfactory.  Ample  exposures  and 
somewhat  weak  solutions  give  slow  develop- 
ment, rarely  failing  to  produce  better  results 
than  short  exposures  and  energetic  developers. 

Frilling  and  Fixation.  In  the  earlier  days 
of  gelatine  dry  plates,  frilling  was  by  no 
means  an  uncommon  occurrence,  the  entire 
film  quite  frequently  leaving  the  plate  during 
the  washing  after  development,  and  at  times 
becoming  completely  disintegrated.    Although 


134       THE    A    B    C    OF    PHOTO  -  MICROGRAPHY 

these  imperfections  are  now  almost  unknown, 
there  are  still  some  makes  of  plates,  the  films 
of  which  are  so  soft  as  to  chip  or  rub  off  in 
patches  all  around  their  edges,  even  under 
the  most  careful  handling,  giving  them  a 
most  unsightly  appearance  to  say  the  least, 
and  often  spoiling  a  subject  which  nearly 
covers  the  plate.  Several  remedies  are  sug- 
gested. If  the  negative  is  transferred  directly 
from  the  developer  to  a  fairly  strong  chrome- 
alum  bath,  in  which  it  should  be  left  several 
minutes,  the  film  will  usually  be  sufficiently 
hardened  to  prevent  any  rubbing  off  at  the 
edges.  But  mark  carefully,  the  plate  must  be 
thoroughly  washed  previous  to  being  placed  in 
the  fixing  bath,  in  order  to  remove  the  alum 
which  greatly  retards  action  of  the  hypo.  It 
must  not  be  forgotten  that  complete  fixation 
and  removal  of  the  last  trace  of  hypo  are 
essential  to  the  permanence  of  a  negative. 
Therefore,  the  washing  after  treatment  with 
alum  must  not  only  be  very  thorough,  but 
the  negative  should  be  allowed  to  remain  in 
the  fixing  bath  for  a  considerable  time  after 
the  white  has  entirely  disappeared  from  its 
back,  and  the  final  washing  cannot  well  be 
too  prolonged  or  complete.  I  desire  to  urge 
this  most  earnestly  upon  all  my  readers  who 


GENERAL     NOTES  135 

wish  perfection  and  permanency  in  their  neg- 
atives. A  formaldehyde  bath,  in  the  propor- 
tions of  one  drachm  to  eight  ounces  of  water, 
answers  the  same  purpose  as  alum  and  in  a 
better  manner.  It  is  my  own  favorite  means 
of  hardening  a  film.  An  excellent  method  of 
preventing  the  film  from  breaking  off  around 
the  edges  is  to  rub  it  to  the  depth  of  about 
one-eighth  inch  with  a  piece  of  soft  paraffine 
wax  before  development. 

Box  for  Fixing  Bath,  If  but  a  few  nega- 
tives are  made  at  one  time,  a  hard-rubber  or 
agate-ware  tray  will  answer  quite  well  for 
holding  the  hypo  bath,  as  was  pointed  out 
in  the  chapter  on  negative  making.  The 
principal  objections  to  such  a  receptacle  are 
slower  and  less  even  fixation,  and  the  in- 
creased danger  of  scratching  or  otherwise 
defacing  the  moist  and  tender  films.  A 
grooved  box,  in  which  the  plates  stand  on 
edge,  is  far  better  in  every  way.  But  you 
are  warned  to  be  very  careful  in  selecting 
such  a  box,  to  see  that  it  is  made  of  hard 
rubber,  which  will  be  found  practically  inde- 
structible. On  no  account  take  one  of  papier 
mache.  It  may  look  better  and  cost  less 
than  the  rubber  one,  but  is  a  delusion  and  a 
snare.     The  sharp  edges  of  plates  when  low- 


136       THE    A    B    C    OF    PHOTO  -  MICROGRAPHY 

ered  into  the  grooves  will  speedily  cut 
through  the  enamel  or  varnish,  exposing  the 
paper  fabric  to  action  of  the  hypo,  and  then 
very  soon  its  life  will  be  ended. 

Washing  Box.  A  tray  will  answer  for  final 
washing  of  the  plates,  but  is  not  recom- 
mended, especially  if  a  number  are  to  be 
done  at  one  time.  There  is  great  danger  of 
scratching  the  soft,  wet  films;  and  if  the 
water  contains  any  dirt  in  suspension,  it  is 
sure  to  settle  upon  their  surfaces.  Washing 
boxes,  as  now  made,  will  carry  any  size  of 
plates  up  to  their  full  capacity.  These  stand 
on  their  edges,  and  the  water  being  admitted 
at  the  bottom,  flows  upward  until  the  box 
is  filled  and  the  overflow  runs  off^  at  top. 
This  not  only  washes  the  plates  better  than 
it  can  be  done  in  a  flat  tray,  but  in  less  time 
and  with  greater  safety  from  damage.  If 
there  be  no  supply  of  running  water  at  hand, 
a  cork  may  be  inserted  in  the  intake  at  bot- 
tom and  the  box  filled  from  a  pail,  changing 
the  water  several  times  by  removing  the  cork, 
emptying  and  refilling  box,  until  the  washing 
is  completed. 

Measuring  and  Recording  Amplifications.  I 
would  earnestly  urge  upon  every  photo-mi- 
crographer  the  importance  of  measuring  the 


GENERAL     NOTES  137 

amplification  of  all  exposures  in  diameters 
and  recording  same  in  his  note-book.  This 
is  a  matter  that  is  all  too  frequently  neg- 
lected. It  is  quite  a  common  thing  to  find 
an  article  or  even  a  whole  book  illustrated 
by  drawings,  or  reproductions  of  photo-mi- 
crographs bearing  the  legend  **  highly  magni- 
fied;"—  this  and  nothing  more,  save  the  name 
of  the  subject.  Whether  it  be  amplified  ten, 
or  a  hundred,  or  a  thousand  diameters,  is  all 
one  in  this  slipshod  method  of  announcing 
that  it  is  magnified  at  all.  It  conveys  no  idea 
whatever  to  one  unacquainted  with  the  origi- 
nal as  to  its  actual  size,  or  in  comparison 
with  the  pictured  enlargement.  If  every  one 
making  a  photo  -  micrograph  would  at  the 
time  carefully  measure  its  amplification  in 
diameters  and  make  entry  of  same  in  his 
note-book,  it  would  add  greatly  to  the  prac- 
tical value  of  his  work.  And  it  is  so  readily 
done,  requiring  so  little  time,  such  few  and 
simple  tools,  that  there  is  no  excuse  for  neg- 
lecting it.  A  stage  micrometer  ruled  in  tot 
and  ToVo  of  an  inch  (or  the  metric  scale  if 
preferred);  a  pair  of  dividers  and  a  scale 
divided  in  tenths  of  an  inch,  or  in  milli- 
meters, comprise  all  the  necessary  apparatus. 
The  methods  of  use  are  equally  simple.    They 


138       THE    A    B    C    OF    PHOTO  -  MICROGRAPHY 

are  probably  familiar  to  the  majority  of  my 
readers,  but  at  the  risk  of  repeating  an  oft- 
told  tale  I  will  give  them  once  again.  Let 
us  suppose  that  we  have  just  made  a  nega- 
tive under  a  low  or  medium  power  and  wish 
to  know  the  number  of  diameters  employed 
in  the  making.  Before  changing  the  micro- 
scope or  camera  in  any  manner,  replace  the 
object  with  a  stage  micrometer  ruled  in  parts 
of  an  inch  as  above  and  focus  the  projected 
lines  sharply  upon  the  ground-glass  screen, 
using  those  rho  of  an  inch  apart  for  this 
moderate  enlargement.  Now,  applying  one 
leg  of  the  dividers  to  a  line,  we  extend  the 
point  of  the  other  until  it  rests  upon  the 
next  adjacent  line.  Should  the  distance  from 
point  to  point  be  found  to  measure,  say  just 
one  inch  upon  the  scale,  it  is  obvious  that 
the  enlargement  is  one  hundred  diameters, 
each  hundredth  division  of  the  micrometer 
having  been  magnified  to  that  extent.  Of 
course  this  enlargement  is  equal  in  every 
direction,  —  horizontal,  vertical,  diagonal,  so 
that  in  popular  parlance  it  is  really  ten 
thousand  timesj  or  the  square  of  the  diam- 
eters  ; — the  latter  term  alone  being  used  scien- 
tifically, as  it  is  presumed  my  readers  all 
know  quite  well.      Should   the  divider  points 


GENERAL    NOTES  139 

embrace  but  nine  of  the  one-tenth  divisions 
on  scale,  then  the  amplification  is  shown  to 
be  only  ninety  diameters,  as  five  would  give 
fifty,  etc.  Intermediate  enlargements  between 
the  tenths  must  be  carefully  calculated.  This 
method  is,  perhaps,  not  always  accurate  to 
a  single  diameter,  but  is  sufficiently  so  for 
all  practical  purposes.  If  the  enlargement  is 
more  than  lOO  diameters  it  will  be  well  to 
measure  the  distance  between  two  rulings 
when  using  the  to^  scale.  With  high  pow- 
ers it  will  be  necessary  to  employ  the  toVo 
rulings,  ten  spaces  of  which  enlarged  to 
one  inch  on  the  focusing  screen  are  equal 
to  one  thousand  diameters.  It  will  be  found 
very  useful  to  ascertain  the  exact  camera 
extension  necessary  to  give,  say  lOO,  250, 
500  and  1,000  diameters  with  combinations 
of  the  various  objectives  and  eye-pieces; 
making  records  of  the  same  for  future  use. 
Then,  if  it  be  desired  to  photo-micrograph 
an  object  at  any  particular  number  of  diame- 
ters, by  referring  to  note-book,  the  combina- 
tion of  objective,  ocular  and  camera  exten- 
sion, which  will  give  this  amplification,  may 
be  found  at  once,  thereby  saving  much  time 
and  the  necessity  of  making  fresh  measure- 
ments.    Tissue  work  is  usually  done   under 


140       THE    A    B    C    OF    PHOTO  -  MICROGRAPHY 

low  and  medium  powers,  from  fifty  to  two 
hundred  diameters,  occasionally  reaching  five 
hundred,  but  only  in  more  or  less  rare  cases. 
In  bacterial  work  one  thousand  diameters  is 
the  generally  accepted  enlargement  at  home 
and  abroad.  It  is  sufficiently  high  to  show 
the  more  minute  forms  very  satisfactorily,  is 
within  the  compass  of  all  students'  micro- 
scopes supplied  with  the  usual  iV  oil  immer- 
sion lens,  and  if  universally  adopted  in  pub- 
lished reproductions,  afi^ords  a  very  useful 
standard  for  comparative  sizes  of  the  various 
forms  of  bacteria. 

Ocular  or  No  Ocular?  The  constantly  in- 
creasing use  of  apochromatic  objectives,  due 
both  to  their  many  points  of  superiority  over 
achromats  and  reduced  cost  since  their  early 
introduction,  has  been  a  large  factor,  I  believe, 
in  the  nearly  universal  employment  of  an  eye- 
piece for  photo-micrography  at  the  present 
day.  Time  was,  and  at  no  very  distant  date, 
when  exactly  the  reverse  might  have  been 
said.  The  image  of  an  enlarged  microscopic 
subject  was  projected  by  the  object  glass 
alone;  and  increased  amplification  was  ob- 
tained by  adding  to  the  length  of  bellows 
in  the  camera.  The  late  Dr.  Col.  J.  J.  Wood- 
ward, whose  wonderful  work  has  rarely  been 


GENERAL     NOTES  14^ 

equaled,  and  never  excelled  in  certain  direc- 
tions, never  used  an  eyepiece  in  making  his 
world-famous  negatives.  He  worked  within 
his  camera,  from  which  every  ray  of  light 
was  excluded  that  did  not  pass  through  the 
microscope.  His  lenses  were  perfectly  cor- 
rected in  themselves,  and  did  not  require 
completion  by  means  of  a  compensating  or 
projection  ocular,  as  do  the  present-day  apo- 
chromats.  Had  he  elected  to  use  an  eye- 
piece, it  must  perforce  have  been  one  of  the 
Huyghenian  form,  which  alone  were  available 
in  his  time.  Fortunately  the  judgment  which 
led  him  to  discard  the  ocular  was  not  at 
fault,  since  the  photographic  image  projected 
through  one  of  this  form  is  decidedly  inferior 
in  sharpness  and  brilliancy  to  that  produced 
by  means  of  a  well-corrected  achromatic  ob- 
jective alone,  especially  in  high  powers.  With 
apochromats  and  compensating  oculars,  how- 
ever, the  results  are  reversed,  very  many 
objects  being  resolved  with  a  sharpness  and 
brilliancy  quite  beyond  the  reach  of  the  best 
achromats.  Doubtless,  if  Dr.  Woodward  was 
living  and  working  at  the  present  time,  it 
would  not  be  in  the  darkness  of  his  former 
work-room  camera,  but  with  the  modern  ap- 
pliances in  the  clear  light  of  day. 


142       THE    A    B    C    OF    PHOTO  -  MICROGRAPHY 

And  yet  I  am  constrained  to  enter  a  plea 
in  favor  of  dispensing  with  the  ocular  (cer- 
tainly with  the  Huyghenian  form) ,  in  low  and 
medium  power  work.  You  will  do  more  and 
better  without  than  with  it.  Look  at  the 
section  of  Echinus  spine  (frontispiece  of  this 
book),  made  with  a  cheap  students'  two-third- 
inch  objective  of  two  systems  without  an  eye- 
piece, and  note  its  almost  perfect  definition 
and  flatness  of  field,  together  with  evenness 
of  lighting.  Then  photograph  the  same  sub- 
ject under  the  same  amplification,  using  any 
achromatic  objective  you  may  choose  in  con- 
nection with  a  Huyghenian  eyepiece,  such  as 
accompanies  the  usual  students'  microscope. 
Make  a  print  of  it  and  compare  with  the 
reproduction.  If  it  equals  the  latter  I  shall 
have  nothing  more  to  say  in  favor  of  using 
the  objective  alone.  If  for  any  reason  you 
should  prefer  to  employ  an  ocular,  then  by 
all  means  procure  one  of  Spencer's  Aplanats, 
for  use  with  achromatic  object  glasses,  if  you 
desire  the  best  results  in  your  work. 

Blocking  out  Backgrounds.  Although  the 
details  of  a  negative  must  not  be  retouched  or 
changed  in  any  manner,  it  is  quite  legitimate 
to  block  out  the  background  of  an  object  re- 
quiring to  be  shown  as  a  whole,  by  painting 


GENERAL    NOTES  143 

around  its  margin  —  on  the  film  side  —  with 
some  light-excluding  pigment,  to  the  width  of 
about  a  quarter  of  an  inch.  Then  paste  on  the 
glass  side  a  piece  of  **post  paper"  with  an 
opening  slightly  larger  than  the  object,  which 
will  render  the  negative  opaque  excepting  the 
object  itself,  and  the  print  can  be  made  with  a 
white  and  clear  field.  Figures  9,  24,  and  27 
are  from  negatives  treated  in  this  manner. 

In  bringing  these  notes  to  a  conclusion, 
which  is  also  the  finis  of  this  little  book,  I 
would  say,  in  apology  for  their  being  perhaps 
somewhat  drawn  out,  that  in  the  writing  I 
have  kept  its  title  constantly  in  view,  and 
earnestly  endeavored  to  ground  my  readers 
who  may  have  known  nothing  of  photo-micro- 
graphy, in  the  A  B  C  of  the  science,  or  art, 
before  proceeding  with  more  advanced  les- 
sons. Those  who  have  already  learned  its 
alphabet,  or  crossed  its  "  asses-bridge,"  and 
to  whom  these  details  will  appear  trivial  or 
unnecessary,  may  pass  them  by,  perhaps  pick- 
ing out  a  grain  of  wheat  here  and  there 
among  the  chaff.  To  one  and  all,  however, 
I  extend  my  earnest  wishes  for  their  success 
in  this  fascinating  and  important  work,  urging 
upon  each  the  homely  old  advice — "If  at  first 
you  don't  succeed,  try,  try  again." 


DESCRIPTION    OF    PLATES 


FRONTISPIECE 

Transverse  Section  of  an  Echinus  Spine — Echinometra  lucunter. 
F$r  details f  see  page  5/. 

PLATE   I 

Fig.  I. — Improvised  Photo- micrograph ic  Apparatus. 
See  page  ig. 

Fig.  2. — Adjustable  Photo -micrographic  Camera. 
See  page  21, 

Fig.  3. — The  Author's  Photo -micrographic  Camera. 
See  page  23, 

PLATE    II 

Fig.  4— E.  R.  &  C.  Camera  with  Microscope.    Arranged 

for  use  without  Eye -piece. 

See  page  26- 

Fig.  5. — E.  R.  &  C.  Camera,  and  Microscope  fitted  with  Com- 
pound body  and  Ocular.  The  camera  is  run  back  on  its 
sliding  bed  to  permit  adjustments  of  object  and  illumina- 
tion by  the  microscope. 

See  page  26, 

Fig.  6. — E.  R.  &  C.  Camera   with    Microscope,  arranged 

for  High  Power  Work. 

See  page  26, 

(HS) 


146  DESCRIPTION    OF    PLATES 

PLATE    III 
Low  Powers  by  Transmitted  Light 

Fig.  7. — Carcinoma  of  Mammary  Gland. 
For  details^  see  page  62. 

Fig.  8. —Suctorial  Tubes  in  Tongue  of  Blow-fly. 
For  details y  see  page  dj, 

PLATE    IV 
Medium  Powers  by  Transmitted  Light 

Fig.  9. — Aulacodiscus  Oreganus.     Diatom. 

For  details t  see  page  67, 

Fig.  10.— Human  Voluntary  Muscle.     Injected. 

For  details,  see  page  6g, 

PLATE    V 
High  Powers  by  Transmitted  Light 

Fig.  II.     Karyokinetic  figure  in  a  Leucocyte.     Human. 
For  details,  see  page  yi. 

Fig.  12.— Pleurosigma  angulatum.    "White  dot"  resolution. 
For  details,  see  page  '/j, 

PLATE   VI 

Dark-field  Illumination 

Fig.  13.— Anchors  and  Plates  of  Synapta.     Grouped. 
For  details,  see  page  75. 

Fig.  14. — Heliopelta   euleri.    (Sunshield  Diatom.)    Dr.  Mer- 
cer's Method. 
For  details,  see  page  76, 


DESCRIPTION    OF    PLATES  1 47 

PLATE    VII 
Opaque  Objects 

Fig.  15.— Strewn  Diatoms.     Cuxhaven. 
For  details y  see  page  78, 

Fig.  16,— -Cluster  Cups,     (^cidium  grossularia. ) 
For  details ^  see  page  yg, 

PLATE    VIII 

By  Polarized  Light 

Fig.  17.-— Starch  from  Canna  Root.     (Tous  le  mois.) 
For  details^  see  page  80, 

Fig.  18.— Amygdalin  Crystals. 
For  details  J  see  page  80. 

PLATE    IX 

Bacteriological. 

Fig.  19. — Bacillus  tuberculosis  in  sputum. 

Fig.  20. — Bacillus  anthracis. 

For  details f  see  page  8^. 

PLATE   X 

Bacteriological 

Fig.  21. — Streptococcus  pyogenes,  aureus. 
For  details,  see  page  83, 

Fig.  2a. — Bacillus  Trommel -Schlagel.    (Spores.) 
For  details,  see  page  84, 


148  DESCRIPTION    OF    PLATES 

PLATE    XI 

Photo  -  Macrographs 

Fig.  23. — Corisa  undulata.     Water  Boatman. 

Fig.  24. — Serjania.     Transverse  Section  of  Stem. 

For  details y  see  page  q6, 

PLATE    XII 

Photo - M  acrogr aphs 

Fig.  25. — Mosquito— female.     (Anophele.) 

Fig.  26.— Human  Scalp.     Flat  Section.     Showing   Hairs  cut 

transversely. 

For  details y  see  page  gj. 

PLATE   XIII 

Lantern  Slides 

Fig.  27. — A  Sample  Lantern  Slide.     (Front  view.) 

Fig.  28. — A  Sample  Lantern  Slide.     (Back  view.) 

For  details y  see  page  1 18. 


PLATE    in 


:jy''^>j'f 


Fig.  7 

Carcinoma  of  Mammary  gland  +  90 

Transmitted  light:    Low  power 


Fig.  8 
Tongue  of  Blow-fly  +  50 
Transmitted  light:    Low  power 


PLATE    IV 


Fig.  9 

Aulacodiscus  Oreganus  +  ?I5 
Transmitted  light:    Medium  power 


.%y^^'  „^^-'':m^^ , , 


Fig,  io 

Voluntary  muscle,  Man;    injected  +  200 
Transmitted  light;    Medium  power 


PLATE    V 


Fig.  II 

Karyokinetic  figure  in  a  Leucocyte  -|-  82? 
Transmitted  light:    High  power 


Fig.  12 
Pleurosigma  angulatum  -f  ?ooo 
Transmitted  light:    High  power 


PLATE    VI 


Fig.  h 

Anchors  and  plates  of  Synapta  +  60 
Dark-field   illumination;    Paraboloid 


Fig.  14 

Heliopelta  euleri.     Sunshield  Diatom  +  225 

Dark-field  illumination:     Mercer's  isethod 

Printed  from  a  Positive 


PLATE    VII 


Fig.  15 

Diatoms.     Cuxhaven  +  5? 
Opaque;    by  Reflected   light 


Fig.   16 

^cidium.     Cluster  cups  +  ?o 

Opaque:    by  Reflected  lieht 


PLATE    VIII 


Fig.  17 

Canna-root  starch.     (Tous  le  mois)  +  no 

Polarized  light 


Fig.   18 

Amygdalin  crystals  -f  70 

Polarized  light 


PLATE    IX 


Fig.  19 

Bacillus  tuberculosis  in  sputum  +  1000 

Bacteriological 


Fig.  20 

Bacillus  anthracis.     Spores  +  1000 

Bacteriological 


PLATE    X 


Fig.  21 

Streptococcus  pyogenes  +  looo 

Bacteriological 


Fig.  22 

Bacillus  Trommel-Schlagel,  spores  -f   looo 

Bacteriological 


PLATE    XI 


Fig.  2i 
Corisa  undulata  or  Water  Boatman  +  i% 


Fig.  24 
Serjania.     Trans-section  stem  +  5 


PLATE    XII 


FIG.    25 
Mosquito,  Anophele  +  ?.     Female 


--  \- 


Fig.  26 

Human  scalp.     Flat  section  +  7. 
Hairs  cut  transversely 


PLATE    XIII 


^1 

^' 

:^ 

.1 

.| 

^^ 

V 

^ 
^ 

•s 

.^^ 

"3 

>e 

1 

'SS 

tl  ' 

9. 

^ 

_  c:) 

< 

Fig.  27.     Lantern  slide.     Front 


Fig.  28.     Lantern  slide.     Back 


INDEX 

PAGE 

Abbe's  Substagc  Condensers 13,  67,  120 

Acetylene  Gas  as  Radiant 44 

Achromatic  Condenser i3)  69 

Acid  Fixing  Bath     .    .    .    .    » 30 

Adjustable  Camera,  Bausch  &  Lomb's 21 

Agate  Ware  Developing  Trays 30 

"Agfa"  In4:ensifier 129 

"Agfa"  Reducer 131 

A  Home-made  Camera *..•.,.    90 

An  English  Method  of  Drying  Negatives 62 

An  Optical  Illusion 78 

Aplanatic  Oculars,  Spencer's I2,  52 

Atwood's  Camera-Microscope 8 

Backing  Plates •    37 

Bacteria,  Photo-micrographing 82 

Bausch  Sc  Lomb's  Adjustable  Camera 21 

Bausch  &  Lomb's  Microscopes 10 

Beck's  Objectives 15 

Binding  Lantern  Slides 116 

Blacking  Interior  of  Microscope  Body •   •   •   •   .    53 

Black  Paper  Backing  for  Dry  Plates 38 

Blocking  Out  Negatives 142 

Blue  Prints 109 

Box  for  Fixing  Bath 135 

Box  for  Washing  Plates 136 

Bromide  of  Potassium  as  a  Restrainer  .    •   .    .   .   ..   .   .   .133 

Bull's-Eye  Condenser 13 

Camera,  Bausch  &  Lomb's  Adjustable 21 

Camera,  Leitz'  Upright 22 

(149) 


150  INDEX 

PAGE 

Camera,  Walmsley's  E.  R.  &  C 23 

Camera  and  Photographic  Appliances,  The 18 

Camera-Microscope,  Atwood's 8 

Carbutt's  Dark-room  Lantern 28,  59 

Carbutt's  Orthochromatic  Dry  Plates 36,  69 

Care  of  Dark-room  Lantern 29 

Celluloid  Developing  Trays 30 

Centering  Radiant  and  Condenser , 63 

Coal-oil  Lamp  as  the  Radiant 46,  67 

Color-correct  Dry  Plates 35)  69 

Coloring  Lantern  Slides 115 

Color- Screens  for  Orthochromatic  Plates ,    .    .  57,  68 

Color- Screen   Holder « 72 

Condenser,  Bull's  Eye 13 

Condenser,  Substage 13 

Continental  form  of  Microscopes 10 

Correcting  Objectives  for  Photo -micrography 14 

Cramer's  Orthochromatic  Plates 36  ' 

"Critical"  Illumination 63,72 

Cyanide  of  Silver  Intensifier    .    ^ 127 

Dark-field  Illumination 47,  74 

Dark-field  Photography.     Mercer's  Method 76 

Dark-room,  The 27 

Darlot  Focusing-glass 14 

Davy,  Humphrey:  His  early  Photo-micrographs 3 

Deep  Printing-frame no 

Definition  of  Micro-photograph i,  2 

Definition  of  Photo-macrograph 87 

Definition  of  Photo-micrograph 2 

Density,  Loss  of,  in  Fixing-bath 60 

Density  Reducers 129 

Description  of  Illustrative  Plates 145 

Developers 3I)  33 

Developing  Lanterns 28,  59 

Developing  Trays 30 

Developing  a  Negative 59 


INDEX  151 

PAGE 

Diatoms,  Photographing d'j 

Diffused  Daylight  as  Radiant 42 

Donne,  Dr.     Early  Photo -micrographs  by 4 

Drying  Negatives 61 

Drying  Squeegee  Prints 107 

Earliest  published  Photo-micrographs      4 

Eikonogen 32 

Eiko- Hydro  Developing  Poveders 33 

Electric  Arc  as  the  Radiant ^^ 

Electric  Incandescent  Light  for  Dark-room 27 

Enlarging,  Reducing,  and  Copying  Camera    .   .    .  23,  88,  113 

Exposure,  Length  of 58,  64 

Farmer's  Reducer.    Formula 102 

Ferrotype  Plates  for  Squeegeeing  Prints 104 

Ferrotype,  Care  of 108 

Fiber  Water  Pail 31 

Fine  Adjustment  of  Focus 25,  66 

Finishing  Lantern  Slides 115 

Fixing  after  Development 60,  134 

Fixing-bath  Formula 30 

"Flare  Spot" 53 

Focusing-glass •    •   •   •   •  13,  57 

Focusing-screens , 55 

Folding  Drying-rLck 31 

Forbes'  Lantern  Plates 112 

Forbes'  Orthochromatic  Plates 36,  64,  72 

Form  of  Note-book 120 

Forms  for  Cutting  out  Masks 103 

Formula  for  Backing  Plates 37 

Frilling 133 

General  Notes 119 

Graduates 30 

Hand-feed  Electric  Arc  Lamp 43 

Hard  Rubber  Developing  Trays 30 

Hard  Rubber  Fixing-box    ...., 135 

Heliostat      .   .   .   .   c 42 


152  INDEX 

PACK 

High  Powers,  Subjects  for 50 

High  Powers  with  Transmitted  Light 69 

Holder  for  Color  Screen 72 

Home-made  Camera 90 

Homogeneous  Objectives,  Illuminating  Power  of  ....    .    70 

Huyghenian  Eye-pieces 50 

Hydroquinon 32 

Illumination .    42 

Improvised  Photo-micrographic  Apparatus 19 

Intensification .     124 

Intensifier,  Cyanide  of  Silver 127 

Iris  Diaphragm 57 

Isochromatic  Plates 35 

Karyokinesis 71 

Labeling  Lantern  Slides 117 

Lantern,  The  Dark-room 28 

Lantern  Plates 112 

Lantern  Slides iii 

Langenheim's  Micro -photographs 2 

Leitz's  Microscopes 10 

Leitz's  Upright  Camera 22 

Length  of  Exposure 58,  65,  68,  73 

Leucocytes 71 

Lime-light  as  the  Radiant 44 

Local  Reduction  of  Density 131 

Low  Powers,  Subjects  for 50 

Low  Powers  with  Transmitted  Light 50 

Lumiere's  "Color-correct"  Plates 36 

Maddox,  Dr.  R.  L 5 

Magnesium  as  the  Radiant 43 

Masking  Prints 103 

Measuring  Amplifications 136 

Mechanical  Local  Reduction  of  Density 131 

Mechanical  Stage 54 

Medium  Powers,  Subjects  for 50 

Medium  Powers  with  Transmitted  Light 66 


INDEX  153 

PACK 

Mercer,  Dr.  A.  Clifford 2,  76 

Metallic  Surfaces,  Photo -micrographing 77 

Methods  of  Evenly  Illuminating  the  Field 64 

Metol » 34 

Micro-photographs 2 

Microscope  and  Optical  Apparatus,  The 8 

Microscopes,  Bausch  8c  Lomb's 10 

Microscopes,  Leitz's 10 

Microscopes,  Spencer  Lens  Company's 11,  14,  50 

Microscopes,  The  ^^Continental"  form   .   , 10 

Microscopes,  Zeiss' 10 

Negative  Drying  Racks 31 

Negative  Making 49 

Non-halation  Plates ^.   .   .   .    37 

Note-book 119 

Numbering  Negatives .* 121 

Oblique  Illumination    .    .   •    • 47 

Ocular  or  no  Ocular  ? 140 

Oil  Immersion  Objectives 70 

Old  Developer,  Use  of • 34 

Opaque  Objects  by  Reflected  Light . 47,  77 

Orthochromatic  Plates 35 

Oxy-hydrogen  Light 44 

Paper  Backing  for  Plates 38 

Paraboloid  for  Dark-field  Illumination 16 

Persulphate  of  Ammonium  Reducer 130 

Photo -macrography 3 >  49,  86,  87 

Photo -micrography.  Definition  of 2 

Photo-micrography  in  Metallography 77 

Photo-micrographs  as  Educational  Aids  , 6,  99 

Photo-micrographing  Bacteria 82 

Photo-micrographing  vs^ithout  an  Ocular 51 

Plate-holders 24 

Polarizing  Apparatus  . 16,  80 

Polarized  Light 47,  79 

Potassium  Bromide  as  Restrainer 133 


154  INDEX 

PAGE 

Powell  and  Lealand's  Apochromat  i\  Horn 71 

Printing-frames no 

Printing  Methods 98 

Projection  Oculars 12 

Pyrogallol 32 

Rack  for  Drying  Negatives 31 

Reade,  Rev.  J.  B.     Early  Photo-micrographs  of 4 

Recording  Amplifications 136 

Reducer,  "Agfa" 131 

Reducer,  Farmer's loi,  130 

Reducer,  Persulphate  Ammonium 130 

Restraining  Development ..133 

Revolving-Disc  Paper- Cutter 103 

Rives'  Photographic  Paper 108 

Ross'  Achromatic  Condenser 69 

Rubber  Squeegee 107 

Seymour's  Device  for  Instantaneous  Exposures 18 

Screens  for  Focusing 55 

Spencer  Lens  Company's  Microscopes    .    .    .11,  14,  50,  53,  87 

Squeegeeing  Prints 106 

Stage  Micrometer , 137 

Staining  Bacteria 82 

Storing  Negatives  and  Plates 35, 122 

Substage  Condenser 66,  69 

Sunlight  as  the  Radiant 42 

The  Acetylene  Light  as  Radiant 44 

The  Coal-oil  Lamp  as  Radiant 46 

The  "  Continental "  form  of  Microscope    . 10 

The  Dark-room 27 

The  Electric- arc  as  Radiant 43 

The  Lime- light  as  Radiant 44 

The  Radiant  and  Illumination 42 

The  Wellsbach  Incandescent  Mantle  as  Radiant 45 

The  Three-legged  Focusing  Microscope *  •  i3>  57 

Utilizing  Spoiled  Lantern  Plates 114 

Varnishing  Lantern  Slides 114 


INDEX  155 

PAGE 

Varnishing  Negatives • 123 

Velox  Developing  Papers 98,  loi 

Walmsley's  E.  R.  &  C.  Camera 23,88,113 

Walmsley's  Gelatine  Focusing-screen 55 

Washing-box  for  Negatives 136 

Washing  the  Negative 61 

Watson's  Enlarging  Apparatus 94 

Wedgev^ood's  early  Photo-micrographs 3 

Wellington  and  Ward's  S.  C.  P.  Papers 102 

Welsbach  Incandescent  Mantle  as  Radiant 20,  45 

Wenham's  Method  of  Correcting  Objectives 15 

Woodv^rard,  Dr.  J.  J 5,  52 

Wuestner  Orthochromatic  Plates 65 

Zeiss'  Microscopes 10 


PHOTOGRAPHIC    SUPPLIES 


FOR 


MICROGRAPHIC     WO  RK 

Cameras 

Lenses 

Chemicals 

and 

Photographic 
Materials 

OF  ALL  KINDS 

Send  for  free  Illustrated  Catalogue 


THE  ANTHONY   &   SCOVILL   CO. 

122-124  Fifth  Avenue         -        -         New  York 

ESTABLISHED   1843 


SPENCER 
MICROSCOPES 

AND 

Spencer   O  b j  e  c  t i v  e  s 

are  unexcelled  for 
PHOTO-MICROGRAPHY 

Large  Body-tube ;  Draw-tube  of  standard 
size,  permitting  an  exchange  of  oculars  when 
desired.  Finest  workmanship  in  construction 
and  finish.  SPENCER  OBJECTIVES  are 
famous  for  sharp  definition  and  general  ex- 
cellence. 


SEND  FOR  CATALOGUE 


SPENCER  LENS  COMPANY 

BUFFALO,    NEW  YORK 


THREE    IMPORTANT    BOOKS    FOR 
THE   STUDENT  OF  PHOTOGRAPHY 

Photography  as  a  Fine  Art 

By  Charles  H.  Caffin 

What  can  be  done  with  the  camera  is  here  shown,  not  by  theorizinz,  but  by 
actual  examples  of  the  work  of  some  of  the  greatest  American  photographers.  Mr. 
Caffin's  idea  is  to  show  what  is  worth  striving  for,  and  how  the  masters  of  the 
camera  attain  it.  The  hundred  pictures  are  in  themselves  an  inspiration,  showing 
the  work  of  Alfred  Sticglitz,  Gertrude  Kasebier,  James  T.  Kciley,  Frank  Eugene, 
W.  B.  Dyer,  Clarence  H,  White,  Eduard  Steichen,  etc. 

The  Insect  Book 

By  DR.  L.  O.  HOWARD 

Chief  of  Division  of  Entomology,  U.  S.  Departtiient  of  Agriculture 

16  colored  plates,  32  full-paee  half-tones  and  300  text  cuts  illustrating 

hundreds  of  species. 
A  popular  description  of  North  American  insects,  eivins  full  life  histories 

The  Independent  says:  "One  noteworthy  feature  of  'The  Insect  Book'  is  its 
frequent  direct  indication  of  fields  wherein  special  study  is  likely  to  be  well  re- 
warded." Other  books  in  the  New  Nature  Library  are:  The  Butterfly  Book,  The 
Mushroom  Book,  Nature's  Garden,  Bird  Homes,  Birds  That  Hunt  and  are  Hunted, 
and  Bird  Neighbors. 

Price,  net.  13.00 

Camera  Shots  at  Big  Game 

By  Mr.  and  MRS.  A.  G.  Wallihan 

Theodore  Roosevelt  has  written  an  appreciative  introduction  to  this 
striking  collection  of  wild  animal  photographs — a  collection  absolutely  unique, 
comprising  pictures  at  close  range  of  mountain  lions,  deer,  bear,  elk,  and  nearly 
all  the  wild  animals  of  our  great  West,  taken  in  their  native  haunts  by  the  authors, 
during  the  last  ten  years. 

Over  100  larffe  octavo  paees.  with  50  photogfravures  and   half-tones. 

Price,  net.  $10.00 

For  net  books  tent  by  mail,  add  10  per  cent  of  list  price  for  postage 

DOUBLEDAY,  PAGE  &  COMPANY 

34  Union  Square  East      : :      New  York  City 


GOOD  RESULTS 

can  only  be  obtained  in  Photo-Micrographic  work 
when  perfectly  accurate  apparatus  is  used.    The 

Queen  Microscopes 

are  intelligently  designed  and  accurately  made 
and  adjusted  in  every  way.  Objects  specially 
prepared  for  Photo-Micrography. 

CATALOGUES   SENT   ON   APPLICATION 

BM  Microscopes,  Lenses,  Photo-Micrographic  Apparatus,  etc. 
HH  Projection  Microscope,  Polariscope,  etc. 

QUEEN   &  CO. 

Optical  and  Scientific  Instrument  Works 

1010  Chestnut  Street,   PHILADELPHIA 

59  Fifth  Avenue,  NEW  YORK 


CRAMER'S 

ISOCHROMATIC 

PLATES 

Are  the  most  sensitive  plates  in  the  market 
Made  in  Three  Grades  of  Speed 

SLOW,  MEDIUM 
AND   INSTANTANEOUS 

For  Sale  by  all 
Dealers  in  Photographic  Supplies 

CRAMER  DRY  PLATE  CO. 

ST.  LOUIS,  MO. 

OFFICES   IN 

NEW  YORK,  32  East  10th  Street 

CHICAGO,  Room  705  Cable  Building 

SAN  FRANCISCO,  Room  38,  819  Market  Street 


USE  MALLINCKRODT'S  SODIUM   SULPHITE  ANHYDROUS 
ABSOLUTELY  PURE  FOR  PHOTOGRAPHIC  PURPOSES 


Photo-Micrographic 
Apparatus 


MICROSCOPES 

New  "Standard''  Model.  Specially 
suitable  for  use  with  Photo-Micro- 
graphic Cameras. 

MICRO-OBJECTIVES 

Corrected  for  Photography. 

CAMERAS 

Specially  adapted  and  fitted  with  every 
necessary  movement  for  Photograph- 
ing Microscope  Slides. 

ROSS-ZEISS  "PLANAR" 
LENSES 

For  Photo-Micrographic  Enlarging  and 
Reducing. 


PRICE  «    LISTS     FREE. 

ROSS,  Ltd. 

Manufacturing  Opticians 
111  New  Bond  St.,  London,  W.,  England 


EDWARD    PENNOCK 

IMPORTER  OF  OPTICAL  INSTRUMENTS 
36Q9  Woodland    Ave.,    Philadelphia,    Pa. 


Fine  Microscopes  and  Cameras 

OF    BEST    MAKES 

Aid  in    Selection   Given   when   Desired,     Statement  of 
Your  Wants   Solicited 

I  always  have  bargains  in  SECOND-HAND  MICRO- 
SCOPES and  CAMERAS.  Send  for  Special  Bulletin.  At 
present  I  have  a  few  1901  KORONAS,  with  best 
GUNDLACH  SYMMETRICAL  LENSES  and  latest  Model 
D  Shutter,  at  extremely  low  prices. 

A  SIMPLE  PHOTO-MICRO  CAMERA,  $9.00 

FORBES  ORTHOCHROMATIC  PLATES  of  following 
sizes  kept  in  stock:  3XX4X,  30c.;  4x5,  45c. ;  5x7,  7SC., 
in  either   S    brand   (very  rapid)  or  L   brand  (medium  speed). 


Photo-Micrographic    records   a  re 
best  kept  by  the  ^^  Y  and  E  "  card  system 


ni5 


Subi«ct; 


\tSSue->    Viu»Y\gin   reVvng 


cU66 


Norm<a\ 


Un*> 


rro^egJ.Dfcular  fe*  ^  ^"^'^^   Qchrorw.Co»ON.A.\'o 


mat^ 


»»4 


^^ 


ii0^wg>od:    FofcSs\e's   nxoMxpi^ 


l^ty^ 


T^»cK ^ecj-to^v^ 'Rfe<ioeec\  co»kQ.  q^ 


\t^V\V.     <LOK'Vi-a^'Vs 


We  make  up  cards  and  cabinets  to 
suit  just  your  special  requirements 

YAWMAN   &  ERBE   MFG.  CO.,    ROCHESTER,  N.  Y. 

N.  Y.:  360  Broadway.     [Chicago,  138  "Wabash.  Boston,  92  Franklin 


Photographic  Books 

We  carry  the  largest  and  most  complete 
stock  of  photographic  literature  in  America. 
Any  book  dealing  with  photography  and 
its  applications  can  be  obtained  promptly 
if  not  in  stock  when  order  is  received. 
Descriptive  catalogue  of  200  of  the  best 
photographic    books    free    on    application 

TENNANT  and    WARD 
287  Fourth  Avenue  :  New  York  City 


In  order  to  make  photo- 
micrographs free  from  hala- 
tion use  our 

ORTHONON 
PLATE 

It  is  the  best  all  -  around 
plate  on  the  market. 

SEND    FOR    BOOKLET 

STANDARD    DRY  PLATE  CO. 

(Home   Office)    LEWISTON,    MAINE 

(CHICAGO   :  NEW  YORK 
DEPOTS  IN  1  PHILADELPHIA   :  MONTREAL 


FOR    THE    BEST    RESULTS    IN 

PHOTO-MICROGRAPHY 

Experts   use 

FORBES 

Orthochromatic 
Plates 

S  brand — very  rapid 

L  brand — medium  rapidity 

In  securing  color  values  and  for  general 
excellence  these  plates  are  admittedly 
unsurpassed.  For  full  particulars  apply 
to   your   dealer   or 

FORBES  DRY  PLATE  WORKS 
ROCHESTER,  N.  Y. 

ESTABLISHED  AND  IN    CONTINUOUS  OPERATION    SINCE    1883 


The  most  complete  work  on  the  subject— 1899 

PHOTO-MICROGRAPHY 

A  Manual  for  Beginners  and  Experts 
By  Edmund  J.   Spitta 

With  forty -one  half-tone  reproductions  from  original  nega- 
tives and  sixty-three  text  illustrations. 
163  pages,  8>^  x  11  inches.    Cloth.    Price,  $5.00. 

CONTENTS 
Introduction;  I,  Illuminants;  II,  Low -power  Work;  III, 
Medium-power  Photo-Micrography- Camera  and  Accessories; 
ly,  Microscopes,  Lenses  and  Eye  Pieces  used  in  Medium  and 
High -power  Work;  V,  The  Substage  and  Auxiliary  Condensers, 
and  other  matters  of  importance;  VI,  Medium-power  Work; 
VII,  High-power  or  Critical  Photo- Micrography;  Appendices 
(9)  and  Index. 

Practical  Photo -Micrography 

By  Andrew  Pringle 

160  pages,  with  index  and  many  diagrams.    $2.50. 

This  work,  published  in  1893,  followedthe  author's  larger 
and  more  pretentious  treatise,  now  out  of  print.  It  is  not  illus- 
trated with  examples  of  photo -micrography. 

CONTENTS 
I,  General  Appliances;  II,  Microscope  and  its  Parts;  III, 
Photo-Micrographic  Apparatus;  IV,  Objectives  and  Oculars; 
V,  The  Condenser  and  Its  Fittings;  VI,  Illumination;  VII, 
General  Routine;  VIII,  Photographic  Plates:  Exposure;  IX, 
Color  Treatment  of  Various  Objects;  X,  Black  Backgrounds, 
Reflectors;  XI,  Development  and  Fixing;  XII,  Reduction,  In- 
tensification; XIII,  Printing  on  Gelatino- Chloride  Paper; XIV, 
Bromide  Paper;  XV,  Enlarging  on  Bromide  Paper;  XVI> 
Lantern  Slides ;  XVII,  Microscopical  Technique  and  Prepara- 
tions; Appendix. 

Note.— The  two  books  here  listed  arc  written  from  the  Bnglish  view-point. 

TENNANT  &  WARD 

Pttblish§rs  of  Photographic  Books    :    Catalogug  on  Application. 
287   Fourth   Avenue,   New   York 


THE  PHOTO -MINIATURE 

series    of   little    monographs    on    photography 

offers  the  most  interesting  and  complete  library  available 
for  photographic  reference.  Published  monthly,  at  $2.50 
per  year.  Every  number  complete  in  itself.  43  numbers 
published.  Always  obtainable.  Separate  numbers,  25 
cents  each,  postpaid. 

1.  MODERN  LENSES  (14th  thousand) 

2.  THE  POSE  IN  PORTRAITURE  (14th  thousand) 

3.  HAND-CAMERA  WORK  (13th  thousand) 

4.  PHOTOGRAPHY  OUTDOORS  (13th  thousand) 

5.  STEREOSCOPIC  PHOTOGRAPHY  (8th  thousand) 

6.  ORTHOCHROMATIC  PHOTOGRAPHY  (11th  thousand) 

7.  PLATINOTYPE    PROCESSES  (11th  thousand) 

8.  PHOTOGRAPHY  AT  HOME  (11th  thousand) 

9.  LANTERN  SLIDES  (9th  thousand) 

10.  THE  ••  BLUE  PRINT."  ETC.  (7th  thousand) 

11.  DEVELOPERS   AND   DEVELOPMENT  (14th  thousand) 

13.  RETOUCHING  NEGATIVES  AND   PRINTS  (I4th  thousand) 

13.  PHOTOGRAPHING  FLOWERS  AND  TREES  (8th  thousand) 

14.  STREET    PHOTOGRAPHY  (8th  thousand) 

15.  INTENSIFICATION  AND  REDUCTION  (7th  thousand) 

16.  BROMIDE  PRINTING  AND  ENLARGING  (Uth  thousand) 

17.  THE  CARBON  PROCESS  (8th  thousand) 

18.  CHEMICAL   NOTIONS,  ETC  (7th  thousand) 

19.  PHOTOGRAPHING  CHILDREN   (8th  thousand) 

20.  TRIMMING.  MOUNTING  AND   FRAMING   (8th  thousand) 

21.  ALBUMEN  AND  PLAIN  PAPER  PRINTING 

22.  GUM-BICHROMATE  PRINTING 

23.  PHOTOGRAPHIC  MANIPULATIONS  (8th  thousand) 

24.  PHOTOGRAPHING  CLOUDS  (8th  thousand) 

25.  LANDSCAPE  PHOTOGRAPHY  (8th  thousand) 

26.  TELEPHOTOGRAPHY 

27.  PINHOLE  PHOTOGRAPHY 

28.  SEASHORE  PHOTOGRAPHY 

29.  FLASHLIGHT  PHOTOGRAPHY  (8th  thousand) 

30.  PHOTOGRAPHING  INTERIORS 

31.  PHOTOGRAPHING  AT  NIGHT 

32.  DEFECTS  IN  NEGATIVES 

33.  THE  DARK-ROOM 

34.  DEVELOPMENT  W^ITH  PYRO,   METOL  AND  ORTOL 

35.  ENLARGING  NEGATIVES 

36.  LENS  FACTS  AND  HELPS 

37.  FILM  PHOTOGRAPHY 

38.  COLOR  PHOTOGRAPHY 

39.  PHOTOGRAPHING  ANIMALS 

40.  PLATINOTYPE  MODIFICATIONS 

41.  COPYING  METHODS 

42.  GENRE  PHOTOGRAPHY 

43.  PHOTOGRAPHIC  CHEMICALS 

OTHERS  TO  FOLLOW.    Descriptive  List  on  Application 

TENNANT    &   WARD 
287   Fourth  Avenue  :       :  New  York  City 


THIS   BOOK   IS  DUE  ON  THE   LAST  DATE 
STAMPED   BELOW 


RENEWED   BOOKS  ARE  SUBJECT  TO  IMMEDIATE 
RECALL 


LIBRARY,  UNIVERSITY  OF  CALIFORNIA,  DAVIS 

Book  Slip-Series  458 


328443 


UNIVERSITY  OF  CAUFORNIA  UBRARY  1^ 


